SIRD-904 Radar Level Gauge with Parabolic Antenna

Radar Level Gauge for Automatic Strorage Tank Level Measurement

Radar level gauge is a non-contact level measuring instrument with microwave technolog. No displacement and no transmission parts. Radar level gauge is the perfect choice for non-contact measurement of liquid or material storage tank. Radar level gauges with unique features are an important part of the tank monitoring and control system. Radar level gauge and ultrasonic level transmitter are similar in structure.

  • Application:Solid material, Strong dust, easy to crystallize, condensation occasion
  • Measuring Range:80 meters
  • Process Connection:Thread, Universal Flange
  • Process Temperature:-40℃~130℃(Standard type);-40℃~250℃(High temperature type)
  • Process Pressure:-0.1 ~ 0.3 MPa
  • Measurement Accuracy: ±15mm
  • Protection Grade:IP67
  • Frequency Range: 26GHz
SIRD-904 Radar Level Gauge with Parabolic Antenna

Sino-Inst offers a variety of Radar Level Gauge with Parabolic Antenna for level measurement. If you have any questions, please contact our sales engineers.

Features of SIRD-904 Radar Level Gauge with Parabolic Antenna

Radar Level Gauge with Parabolic Antenna can produce narrow beam width and directivity. When there are many interferences in the tank wall, it can be measured well. It is not affected by false echoes of interferences such as steps.

The parabolic antenna is suitable for liquid and solid applications. Because of the largest diameter, the radar beam is the narrowest and can be used for extremely long measurement distances. The parabola is also the most insensitive antenna type to pollution.

It can be used in applications where antenna condensation is severe, such as asphalt and liquid sulfur.

SIRD-904 Radar Level Gauge with Parabolic Antenna uses a transmission frequency of up to 26GHz. It has:

  • The beam angle is small (minimum 5 degrees). The energy is concentrated. It has stronger anti-interference ability. It greatly improves the measurement accuracy and reliability;
  • The antenna size is small. It is easy to install and add dust cover and other antenna protection devices;
  • The measurement blind area is smaller. Good results can also be obtained for small tank measurement;
  • The wavelength is shorter. It is more suitable for the level measurement of small particles.
  • It adopts advanced microprocessor and unique EchoDiscovery echo processing technology.
  • It adopts pulse working mode. Radar level gauge has very low transmitting power. It can be installed in various metal and non-metal containers, and it has no harm to human body and the environment.

Specifications of SIRD-904 Radar Level Gauge

Application:Solid materials, strong dust, easy to crystallize, and condensation
Measuring Range:80 meters
Process Connection:Thread, universal flange
Process  Temperature:-40~130℃(standard type) / -40~250℃(high temperature type)
Process Pressure:-0.1~0.3MPa
Accuracy:±15mm
Protection Grade:IP67
Frequency Range:26GHz
Supply:Two-wire system (DC24V) / Four-wire system (DC24V/AC220V)
Signal Output:Exia ⅡC T6 Ga / Exd IIC T6 Gb
Outer Covering:Aluminum Single Chamber / Aluminum Dual Chamber / Plastic / Stainless Steel Single Chamber
Explosion-proof Grade:4…20mA/HART (two-wire/four-wire) / RS485 Mod bus
Antenna Materialstainless steel

Radar level gauge working principle

Radar level gauge antenna microwave pulse is narrow, the downward transmission antenna. Microwave exposure to the medium surface is reflected back again by the antenna system receives. Sends the signal to the electronic circuit automatically converted into level signals. Because the microwave propagation speed, electromagnetic wave to reach the target and the reflected back to the receiver this time is almost instantaneous.

Datum measurement:  Screw thread bottom or the sealing surface of the flange.

Note: Make sure the radar level meter the highest level cannot enter the measuring blind area (Figure D shown below).

  • A    Range set
  • B    Low adjustment
  • C    High
  • D    Blind area

Radar Level Gauge Applications

Radar liquid level can be divided according to the antenna form and can be divided into cone antenna, parabolic antenna, rod antenna.

The cone antenna is suitable for installation on the top of the tank or on the still pipe. Suitable for applications with a large measuring range.

The parabolic antenna is suitable for both liquid and solid measurement applications. Because it has the largest diameter, it has the narrowest radar beam.

The parabolic antenna is also the antenna type that is least sensitive to pollution. Which can be used for extremely long-distance measurement. It can be used in applications with harsh antenna bonding fluids such as asphalt and liquid sulfur.

The rod antenna is small in size, and only the PTFE material is exposed to the atmosphere of the storage tank. Rod antennas are suitable for measurement applications with sanitary requirements or corrosive chemical materials.

For the measurement-level high-precision radar level gauge, the frequency modulated continuous wave type is adopted. Except for fuel oil, asphalt, and other storage tanks with high viscosity and easy condensation. Which use parabolic antennas, other storage tanks use cone antennas.

The inner floating roof tank is designed with a waveguide to achieving accurate measurement of the liquid level of the storage tank. And set up a local indicator on the ground to display the liquid level value. It is convenient for on-site operators to inspect.

Extended reading: Radar Level Meter for Corrosive Liquids

Radar Tank Gauging System

Liquid level measurement system based on fieldbus of radar level gauge.

The radar level gauge provides 4-20mA output signal superimposed with HART, and also provides a digital field bus transmission method.

In the tank area measurement system, the tank area measurement signal is transmitted to the control system through the field bus of the radar level gauge.

The field bus can transmit multiple process parameters at the same time, which greatly simplifies the connection line and reduces the cost.

And at the same time of the transmission process, the identifier of the instrument and simple diagnostic information can also be transmitted together.

The field bus is bidirectional, so it is possible to calibrate, adjust and operate the field intelligent instrument in the control room. It can even predict the failure before it occurs.

Using the characteristics of data transmission based on the fieldbus of the radar level gauge, a level measurement system is constructed for the tank farm.

A radar level gauge is used for level measurement.
It communicates with the radar communication unit installed in the control room through the field bus.

Then the radar communication unit communicates with the control system through the RS-485 bus. While transmitting the liquid level of each storage tank, the temperature, pressure, density and other detection signals are accurately transmitted to the control system through the radar level gauge for concentration. Monitoring.

Realize the measurement of the entire tank area.

The fieldbus transmission mode of radar level gauge has the following advantages in project implementation:

  1. The use of fieldbus network. It solves the problem of centralized detection of distributed oil storage tanks. It is convenient for networked management. It makes the system more practical, stable and reliable.
  2. Digital transmission method. It can transmit multiple process variables at the same time. It greatly simplifies the signal connection line. It saves a lot of cables, protective sleeves, trough boxes, bridges and threading boxes and other corresponding auxiliary materials. It greatly reduces the cost .
  3. The wiring is simple. If you need to add field instruments, you only need to connect to the original network in parallel. There is no need to lay it in the cabinet room. It saves cables and reduces investment. It also reduces the workload of design and installation.
  4. Project implementation is more convenient. The project period is short. The workload is greatly reduced. The maintenance and installation costs are reduced.

Radar Level Gauge can also be used with paperless recorder.

Radar level measurement refers to the operation method of using radar as the core technology to measure the liquid level value.

Radar level measurement is a radar level gauge based on the principle of time domain reflection (TDR).
The electromagnetic pulse of the radar level gauge propagates along the steel cable or probe at the speed of light.

When encountering the surface of the measured medium. Part of the pulse of the radar level gauge is reflected to form an echo and returns to the pulse transmitter along the same path.

The distance between the transmitting device and the surface of the measured medium is proportional to the propagation time of the pulse between them. The height of the liquid level is calculated.

Extended reading: guided wave radar level sensor advantages and disadvantages

Regarding the price of radar level gauge. Everyone must first know that the price of radar level gauges is generally high. At least under the same measurement parameters. Radar level gauges are more expensive than ultrasonic level transmitters.

However, the price of the radar level gauge is also telling the user its value. After all, you get what you pay for.

Of course. As a manufacturer of radar level gauges. Sino-Inst is committed to providing you with the best price radar level gauge.

Here, we provide you with a price list of radar level gauges. for reference only.

If you need to purchase radar level gauges, please contact our sales engineers to confirm the price.

Radar level gauge price list
ModelUnit price (USD/pc)Medium
Radar level gauge1038 Liquid, gas
Radar level gauge1292 Liquid, solid
Radar level gauge1292 Liquid, solid
Guided wave radar level gauge923 Liquid, gas
High frequency radar level meter1385 Liquid, solid
Guided wave radar level gauge831 Liquid, solid
Anticorrosion radar level gauge1038 Liquid, gas
Rod radar level gauge923 Liquid, solid
Rod guided wave radar level gauge831 Liquid, solid
Cable guided wave radar level gauge831 Liquid, solid

Extended Reading: Influence of Dielectric Constant on Liquid Level Measurement | Radar-Guided Wave Radar Level Meter

Difference 1. The measuring range is different

Ultrasonic liquid level measurement range: 0-50 meters;

The radar level gauge can measure all media with a dielectric constant >1.2 in vacuum. The measuring range can reach 70 meters.

Difference 2: Different emission materials

The ultrasonic level gauge emits sound waves from the sensor (transducer). After being reflected by the liquid surface, it is received by the same sensor or ultrasonic receiver;

Very short microwave pulses with very low energy emitted by the radar level gauge are transmitted and received through the antenna system. Radar waves travel at the speed of light.

Parabolic antenna

The parabolic antenna is suitable for both liquid and solid applications. As it has the largest diameter it has the most narrow radar beam and can be used for extremely long measuring distances. The parabolic is also the antenna type most insensitive to contamination. It can be used in applications with severe antenna condensation like asphalt and liquid sulphur.

The Rosemount 5900S antennas have a drip-off design which for some versions also include inclined polished PTFE surfaces. Condensation on the antenna is minimized, and the radar signal remains strong. This results in maintenance free operation, high accuracy and reliability.

There is always a suitable antenna for every tank type, tank opening and application:

  • Parabolic
  • Horn
  • Still-pipe array
  • LPG/LNG

Information Sources: https://www.emerson.com/documents/automation/product-data-sheet-rosemount-5900s-radar-level-gauge-en-104522.pdf

SIRD-904 Radar Level Gauge with Parabolic Antenna is a cheap alternative to Rosemount 5900S. If you have any technical questions, please contact our sales engineers.

Radar Antenna Types, please refer to:

Oil-water Interface Level Measurement Guide

Interface level measurement is very important for oil and gas, chemical tanks. At the same time, Interface level measurement is also a measurement and control challenge. In today’s increasingly modernized oilfield production, automated crude oil processing has become a guarantee…

Diesel fuel tank level gauges & Indicators

Diesel fuel tank level gauges for industrial oil storage tanks are very important, for level monitoring. Can be divided into mechanical and electronic. Featured Diesel fuel tank level gauges for Sale Read more about 7 Level Senors for Tank Level…

Oil Level Measurement Solutions for the Oil & Gas Industry

Oil Level measurements are necessary to control the amount of oil in the tank and to prevent overflow. Oil Level measurements are very important in the process of oil and gas storage and transportation. We will analyze and introduce the…

Industrial Tank level indicators and Tank Level Gauges

Tank level indicators are level gauges that can measure and display the level of industrial liquid storage tanks. Liquid level refers to the level of liquid in a sealed container (for example oil/fuel tank) or an open container (water tank)…

Non Contact Liquid Level Sensor

The Non Contact Liquid Level Sensor is not in contact with the measured medium. The Non Contact Liquid Level Sensors provided by Sino-Inst is not Gravity Non-contact Liquid Level Sensors. It is the liquid level sensor used in industrial tanks,…

Procurement Guide: Ultrasonic liquid level sensors

Ultrasonic liquid level sensors realize the non-contact continuous detection of liquid level. Hope you can purchase Ultrasonic liquid level sensors at the best price after reading this Procurement Guide. Featured Ultrasonic liquid level sensors You can choose the appropriate Ultrasonic…

Level Measurement: Liquid Chlorine Storage Tanks

Monitoring the level of liquid chlorine storage tanks is a common problem in the chlor-alkali industry. This article combines the application and comparison of the actual use of the liquid chlorine storage tank level measurement level gauge, which has practical…

FAQ

How a radar level gauge works?

The radar level gauge antenna emits narrow microwave pulses. Downward transmission via the antenna. After the microwave touches the surface of the measured medium, it is reflected back and received by the antenna system again. The signal transmitted to the electronic circuit is automatically converted into a level signal. Because microwaves travel so fast, the time it takes for electromagnetic waves to reach the target and return to the receiver by reflection is almost instantaneous.

How do you calibrate radar type level transmitter?

Set up the guided wave radar level transmitter,
HART communicator, power supply,
and the multimeter as below (see below calibration setup Diagram).
Check the configuration of the lower range value (0% level, 4 mA) and high range value (100% level, 20 mA). Make sure that the inputted data is as per the datasheet.
For example, the lower range value is 10 inch and the high range value is 35 inch (both of it are measured from the bottom of level transmitter probe)
Fill the level transmitter chamber with water up to the 0% level. Read the level measurement in the transmitter LCD (or in the HART communicator). Set this condition as 0% level through HART communicator.
Read the mA output of the transmitter by using a multimeter. Adjust (if any) through the HART communicator so that the output of the transmitter (on the multimeter) is 4 mA.
Fill the level transmitter chamber with water up to the 100% level. Read the level measurement in the transmitter LCD (or in the HART communicator). Set this condition as 100% level through HART communicator.
Read the mA output of the transmitter by using a multimeter. Adjust (if any) through the HART communicator so that the output of the transmitter (on the multimeter) is 20 mA.

Request a Quote

Please enable JavaScript in your browser to submit the form

Temperature Sensor Transmitter—-Do You Know?

Temperature sensor transmitter is a combination of temperature sensor and temperature transmitter. It can be used in chemistry and medicine.

Thermocouple, thermal resistance and temperature transmitter of SBW series are the temperature transmitter units of on-site installation type in DDZ series instruments and they are used by matching with industrial thermocouple, thermal resistance. It uses dual-wire transmission mode(two conducting wires are used as the common transmission lines for power input and signal output).

It transforms the industrial thermocouple, thermal resistance signal into 4-20mA and 0-10 mA output signals which are linear with input signal and temperature signal. The transmitter can be directly installed in the junction box of the thermocouple and thermal resistance so as to form an integrated structure. As the temperature measuring instruments of new generation, it is widely used in metallurgy, petroleum, chemical industry, electric power, light industry, textile, food, national defense, scientific research and other industrial sectors.

Sino-Inst offers a variety of Temperature sensor transmitter. If you have any questions, please contact our sales engineers.

The Difference Between Temperature Sensor Transmitter

A temperature sensor refers to a sensor that can sense temperature and convert it into a usable output signal. Temperature sensor is the core part of temperature measuring instrument, and there are many types. According to the measurement method, it can be divided into two categories: contact type and non-contact type.

Temperature transmitter uses thermocouple and thermal resistance as temperature measuring elementAfter measurement, the output signal is sent to the transmitter after voltage stability filtering, operational amplification, nonlinear correction, V/I conversion, constant current and reverse

Temperature sensor transmitter is a combination of temperature sensor and temperature transmitter.

read more about Temperature sensor transmitter

The Function Of The Temperature Transmitter

A temperature transmitter is an instrument that converts a temperature variable into a standard output signal that can be transmitted.Mainly used for the measurement and control of temperature parameters in industrial processes.
The temperature current transmitter converts the signal of the temperature sensor into a current signal, and connects it to an auxiliary instrument to display the corresponding temperature.

Advantage Analysis

  • High precision
  • The range and zero point can be continuously adjusted from the outside
  • Good stability
  • Positive mobility can reach 500%, negative mobility can reach 600%
  • Two-wire system, three-wire system, four-wire system
  • Adjustable damping, overvoltage resistance
  • Solid state sensor design
  • No mechanical moving parts, less maintenance
  • Light weight (2.4kg)
  • Full series of unified structure, strong interchangeability
  • Miniaturization (total height 166mm)
  • The diaphragm material contact medium is optional
  • Unilateral overpressure
  • Low-pressure casting aluminum alloy shell
  • Superior measurement performance, used for pressure, differential pressure, liquid level, flow measurement

Technical Parameter

1. input
Thermocouple: (two wire system), voltage: connect cable:sensor lead, maximum impedance 1.5k
Thermal resistance: (three wire system, four wire system), resistance measurement: connect cable: resistance compensation can reach 50.
2.output Isolated voltage 0.5kV instead of 2.5KV
3.Transmitter input options, accuracy and environmental temperature impact.

How Does A Thermocouple Transmitter Work?

Thermocouple or thermal resistance sensor will be converted into electrical signal by the temperature and then, the signal is sent to the input network of the transmitter which is consisted of zero adjustment circuit, a thermocouple compensation circuit and other related circuits. The signal after zero adjustment will be input to the operational amplifier for signal amplification. The signal after amplification will be output as 4 ~ 20mA DC after being processed by the V/I converter in one way; in another way, it will be displayed in gauge outfit after being processed by A/D converter.

There are two kinds of linear circuit in the transmitter, both of which adopt the feedback mode. The thermal resistance sensor is corrected by the positive feedback mode while the thermocouple sensor is corrected by approximation method of multiple-segment line. There are two kinds of display modes for the temperature transmitter of integrated digital display. The temperature transmitter displayed by LCD is output by the two-wire system while the temperature transmitter displayed by LED is output by the three-wire system.

  1. Bimetal sensor:The bimetal consists of two pieces of metal with different expansion coefficients glued together. As temperature changes, material A will expand more than other metals, causing the metal plate to bend. The curvature of the bend can be converted into an output signal.
  2. Bimetal rod and metal tube sensor:As the temperature rises, the length of the metal pipe (material A) increases,but the length of the unexpanded steel pipe (metal B) does not increase, so due to the change in position, the linear expansion of the metal pipe can be transmitted. Furthermore, this linear expansion can be converted into an output signal.
  3. Sensor designed for liquid and gas deformation curve:When the temperature changes, the volume of liquid and gas will change accordingly.

Various types of structures can convert this expansion change into a position change, thereby generating a position change.

Bimetallic Thermometer
SIRD-903 26 GHz Radar level Sensor

Request a Quote

Please enable JavaScript in your browser to submit the form

SIRD-903 Radar level sensor for solids – Dust solid level measurement

Level sensor for solids is suitable for measuring the level of Dry Material (Bulk Solids and Powders). There are many kinds of meters that can automatically and continuously detect the material level. Such as electrode type, ultrasonic type, heavy hammer type, and so on. The radar level sensor stands out because of its high-precision performance. Radar level sensors can perform reliable level measurements of dust-containing particles, granules, powder, or aggregates in silos, silos, crushers, stockpiles, or transfer station applications. It is suitable for occasions with large changes in dust, temperature and pressure, and the presence of inert gas and steam.

Features of SIRD-903 Radar level Sensor for solid

  • Non-contact measurement. No wear, no pollution
  • Small antenna size, easy to install
  • The wavelength is shorter. It has a better reflection on the inclined solid surface
  • The measurement blind zone is smaller. Good results can also be obtained for small tank measurement
  • The beam angle is small and the energy is concentrated. While enhancing the echo ability, it also helps avoid interference
  • Almost unaffected by water vapor in the atmosphere, temperature, and pressure changes
  • The instrument can also accurately read the true level echo in a severe dust environment
  • High signal-to-noise ratio. Better performance can be obtained even under fluctuating conditions
  • 26GHz frequency. It is the best choice for measuring solid and low dielectric constant media

Specifications of SIRD-903 26 GHz Radar level Sensor

Application:Solid materials, strong dust, easy to crystallize, and condensation
Measuring Range:70 meters
Process Connection:Universal flange
Process  Temperature:-40~130℃(standard type) / -40~250℃(high temperature type)
Process Pressure:-0.1~4.0 MPa (flat flange) -0.1~0.3 MPa (universal flange)
Accuracy:±15mm
Protection Grade:IP67
Frequency Range:26GHz
Supply:Two-wire system (DC24V) / Four-wire system (DC24V/AC220V)
Signal Output:Exia ⅡC T6 Ga / Exd IIC T6 Gb
Outer Covering:Aluminum Single Chamber / Aluminum Dual Chamber / Plastic / Stainless Steel Single Chamber
Explosion-proof Grade:4…20mA/HART (two-wire/four-wire) / RS485 Mod bus
Antenna MaterialStainless steel

Applications of Radar level Sensor for solids – Dust solid level measurement

Radar level sensors for solids can measure the maximum distance up to 70 meters. Compared with ordinary measuring instruments, the antenna of the Radar level sensor is further optimized and processed with a new type of fast microprocessor. Signal analysis and processing at a higher rate can be performed. The application range of Radar level sensors includes solid materials, process containers, or strong dust that are easy to crystallize and dew.

1. Granular materials

In cement plants, most of the raw materials are granular materials, and some are block materials. Such as limestone, raw coal, shale, etc., the semi-finished clinker is also a granular material. Stored in a warehouse or warehouse, there is an angle of repose of the material, but there is also a reflective interface.

According to the angle of repose and surface condition of the material formed by the feeding and unloading. After determining the effective range, it is recommended to use a non-contact Radar level sensor. That is a level gauge with a rod-shaped or horn-shaped antenna. The level gauge of the horn antenna has a stronger echo and higher accuracy (±0.2%~±1%F.S).

2. Powdery materials

There are generally 4 to 8 cement warehouses in cement plants or grinding stations. In addition, there are raw meal homogenization silo and fly ash silo, which is all powdered materials. Because the surface of the powder is extremely loose, microwave reflection is quite difficult. If the Radar level sensor is not used, it is very difficult to measure its level.

For powdery materials, a non-contact Radar level sensor with a horn antenna with a large flange can be used. It actually uses the cable as both an antenna and a still pipe, combining the two into one.

After the microwave pulse is emitted from the probe, it propagates along the cable. When the pulse meets the surface of the material, it will be reflected back, and its range can reach 35m. The dielectric constant ε of the tested material is at least 1.6. In addition, the cable’s wear resistance and the maximum endurable pull-down force. It can meet the testing requirements of various powder storages in cement plants.

At present, many cement plants have used the cable Radar level sensor to measure the material level of the homogenization silo, cement silo, and fly ash silo. Both have achieved good results.

Extended Reading: FMCW Radar for High Temperature Level Sensor

Solid level measurement techniques

Solid level measurement is a challenge for everyone. Because the bulk solids detected in the silo or storage tank are irregular physical forms.

Solid level measurement is a very difficult task. But knowing the amount of bulk solids in a silo, storage tank, or other container is an important variable in any process. Manufacturers can maximize efficiency, prevent overflow, exhaustion, or track volume or quality.

The use and selection of the Solid level measurement instrument are more complicated. Because the tested medium is an irregular physical form. SIRD-903 26 GHz Radar level Sensor is suitable for Dust solid level measurement. It is used in solid materials, strong dust, easy to crystallize, and condensation. Such as calcium carbonate powder level measurement.

Extended reading: ​Solid flow meter | For bulk solids-powder-soybean-cement 

Common level sensors for solids

The analysis of common level sensor for solids is as follows:

No.TypePros and cons
1Rotary resistance level sensorAdvantages: more reliable;
Limitations: Not durable.
2Capacitive level sensorAdvantages: more durable;
Limitations: Poor reliability.
3Permanent magnet level sensorAdvantages: reliable, sensitive, and durable;
Limitations: It must be installed vertically.
4Ultrasonic level sensorAdvantages: non-contact.
Limitations: Dust influence/concave-convex surface influence/noise non-contact type;
5Radar level sensorAdvantages: non-contact.
Limitations: required dielectric constant/dust influence/concave-convex surface influence;
Recommendation: use a four-wire radar with a high transmitting frequency
6Guided wave radar level sensorAdvantages: measurement of a certain point.
Limitations: The dielectric constant has requirements/hanging materials/tension influence;
Extended reading: GWR Solid Level Sensor-for Cement silo-Ash powder measure
7Laser level sensorAdvantages: non-contact
Limitations: Dust influence/concave-convex surface influence
8RF admittance level sensor (capacitive level sensor)Advantages: point contact
Limitations: required dielectric constant/time drift/temperature drift/hanging material/tension;
9Hammer type level sensorTwo types: cable type and belt type
Advantages: direct measurement/manual control
Limitations: traditional cable-type heavy hammers are prone to broken hammers, buried hammers, and messy ropes
Recommendation: Belt type heavy hammer
10Ray level sensorAdvantages: non-contact, stable
Limitations: Pollution/High price
11Weighing type level sensorAdvantages: can measure mass/volume
Limitations: Anti-seismic problem / unknown material condition / high price

Extended reading: Radar Level Meter for Corrosive Liquids

The ultrasonic pulse emitted by the ultrasonic transducer is transmitted to the surface of the object to be measured through the propagation of coal qualification. After reflection, it returns to the receiving transducer through the sound transmission medium.

Measure the time that the ultrasonic pulse propagates in the sound transmission medium from the transmission to the reception. Then according to the speed of sound in the sound transmission medium, the distance from the transducer to the object surface can be calculated. To determine the level.

Capacitance level detectors are also known as Capacitance level transmitters, are also referred to as radio frequency (RF) or admittance level sensors. They operate in the low MHz radiofrequency range, measuring admittance of an alternating current (ac) circuit that varies with level. Capacitance level sensors are a proven, as well as a cost-effective solution for level measurement, and point level detection in liquids and bulk solids. Various transmitters for continuous level measurement and switches, for point level detection are available. The measurement of the interface is also possible. The measuring principle is proven in millions of applications.

Extended reading: GWR Solid Level Sensor-Cement silo-Ash powder measure

Featured level sensors for solids and liquids

FAQ

What are the different types of level measurement?

Types of Level Transmitters:
Level measurement transmitters are of seven types. Each type of transmitter works in a different way and makes it useful for different types of processes.
Capacitance Level Transmitters
Hydrostatic Level Transmitters
Magnetic Level Transmitters
Radar Level Transmitters
ultrasonic Level Transmitter
Guided Microwave Level Transmitters
Hydrostatic level transmitters
Extended reading: FMCW Radar Level Transmitter 120GHz

How do you measure silo levels?

Silo Level Sensor is specially used for level measurement of solid material silos (including fine ore silos). Perfect Solutions for Silo Level Monitoring and Control.
SI-FMF21 FMCW Radar Silo Level Sensor adopts 120GHz FM continuous wave technology, 10GHz sweep bandwidth, and has electromagnetic characteristics in the terahertz band. It has the ability to penetrate materials with a small dielectric constant. In a strong adhesion and strong dust environment, the measurement is stable without interference and does not require any purge device. The measuring distance can reach 150 meters. Perfect solutions in continuous level measurement and remote inventory management systems.Like the storage of powders & bulk solids in bins, silos, vessels, etc.

How are water levels measured?

The Water level sensor mainly has contact type and non-contact type. Different water level sensors have different working principles.
1. The first type is contact. Including single flange static pressure / double flange differential pressure liquid level transmitter, float type liquid level transmitter, magnetic liquid level transmitter, input type liquid level transmitter, electric inner float level transmission Devices, electric float level transmitters, capacitive level transmitters, magnetostrictive level transmitters, service level transmitters, etc.
2. The second type is non-contact. Divided into the ultrasonic liquid level transmitter, radar liquid level transmitter, etc.

Extended reading: Ultrasonic Level Switch-External Mounted

Extended reading: guided wave radar level sensor advantages and disadvantages

Sino-Inst offers over 10 Radar level sensor for solids level measurement. About 50% of these are Radar level meters, 40% is the tank level sensor.

A wide variety of level sensor for solids level measurement options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of radar level measurement instrumentation, located in China.

Request a Quote

SIRD-902T Microwave Radar Liquid Level Sensor

Radar Liquid Level Sensor is an instrument that measures the height of a liquid and converts it into an electrical signal. Using time-domain reflectometry (TDR) sensing technology, Radar Liquid Level Sensor emits and receives high-frequency radio waves (microwaves) to measure the distance to the surface of liquid-based substances. Different from the ultrasonic and guided wave radar transmitter. SIRD-902T Microwave Radar Liquid Level Sensor is a self-heating microwave level sensor. Low-temperature resistance, heat tracing type, non-icing, and anti-crystallization. Suitable for corrosive liquids, steam, and volatile liquids.

Features of SIRD-902T Microwave Radar Liquid Level Sensor

  • The level sensor can be heated. It is resistant to low temperature, self-heating, does not freeze, and prevents crystallization.
  • Almost unaffected by corrosion and foam. Almost unaffected by atmospheric water vapor, temperature, and pressure changes.
  • The severe dust environment has little effect on the work of the high-frequency level meter.
  • The wavelength is shorter. It has a better reflection on the inclined solid surface.
  • The beam angle is small, the energy is concentrated, and the echo ability is enhanced, but it is also beneficial to avoid interference.
  • The measurement blind zone is smaller. Good results can also be obtained for small tank measurements.
  • High signal-to-noise ratio. Better performance can be obtained even under fluctuating conditions.
  • High frequency. It is a better choice for measuring solid and low dielectric constant medium.

Specifications of SIRD-902T Microwave Radar Liquid Level Sensor

Application:Temperature, pressure, slightly corrosive liquid
Measuring Range:20 meters
Process Connection:Thread, flange
Process  Temperature:-40~130℃(standard type) / -40~250℃(high temperature type)
Process Pressure:-0.1~2.0MPa
Accuracy:±3mm
Protection Grade:IP67
Frequency Range:26GHz
Supply:Two-wire system (DC24V) / Four-wire system (DC24V/AC220V)
Signal Output:Exia ⅡC T6 Ga / Exd IIC T6 Gb
Outer Covering:Aluminum Single Chamber / Aluminum Dual Chamber / Plastic / Stainless Steel Single Chamber
Explosion-proof Grade:4…20mA/HART (two-wire/four-wire) / RS485 Mod bus
Antenna MaterialStainless Steel  /  PTFE

Radar Level Sensor Application

The measurable conditions of the 902T Radar Liquid Level Sensor are as follows:

  • Application: corrosive liquid, steam, volatile liquid
  • Measuring range: 20 meters
  • Process connection: flange
  • Medium temperature: -40~130℃ (standard type)/ -40~230℃ (high temperature type)
  • Process pressure: -0.1~2.0MPa

Read more about List of Radar Level Sensors

Radar Liquid Level Sensor Working Principle

The radar-level antenna emits narrow microwave pulses. Downward transmission via the antenna. After the microwave touches the surface of the measured medium, it is reflected back. It is received by the antenna system again and transmitted to the electronic circuit part to automatically convert it into a level signal.

Because microwaves travel so fast, the time it takes for electromagnetic waves to reach the target and return to the receiver by reflection is almost instantaneous.

A range setting
B Low adjustment
C high adjustment
D Blind zone range

The reference plane of the measurement is:
The bottom surface of the thread or the sealing surface of the flange

Note: When using radar level timing, make sure that the highest material level cannot enter the blind area of the measurement (the area shown in D in the figure).

Know more about Level measurement using radar technology

Radar Level Sensor Advantages and Disadvantages

Advantages of radar level measurement

  • Measurement is not affected by temperature, pressure, or dust
  • User-friendly adjustment saves time
  • Non-contact, continuous level measurement over larger ranges
  • Unaffected by sludge and biomass, dust, foam, oil, grease and other coatings, uneven surfaces, turbulence, pressure, and vacuum
  • Single-frequency radar level sensors for liquid sensing, dual-frequency radar level sensors for level measurement of aggregates, gravel, sand, coal, asphalt, and other solids
  • Simple mounting and push-button calibration

Disadvantages of radar level measurement

  • Very sensitive to build-up on the sensor surface.
  • They are very expensive. Price increases with accuracy.
  • Foaming, splashing, vapor, and humidity can affect measurement performance.
  • Top mounting only
  • Minimal blocking distance limits operation when in proximity to liquid level
  • Longer blocking distance than ultrasonic
  • Radar passes through low dielectric constant fluids

Radar Level Sensor for Solids

SI-FMF15 FMCW Radar High-Temperature Level Sensor

Measuring medium: liquid and Solids
Measuring range: 0.1m~120m
Process connection: flange≥DN80
Process temperature: -40~200℃; -60~1200℃
Process pressure: -0.1~2.5MPa
Antenna size: 78mm lens antenna
Antenna material: PTFE/full filling

SI-FMF21 FMCW Radar Silo Level Sensor

Measuring medium: solid
Measuring range: 0.3m~150m
Process connection: flange≥DN80
Process temperature: -40~110℃
Process pressure: -0.1~0.3MPa
Antenna size: 78mm lens antenna + purging (or without purging)
Antenna material: PTFE

SIRD-903 26 GHz Radar level Sensor -Dust solid level measurement

Application: solid materials, strong dust, easy to crystallize, condensation occasions
Measuring range: 70 meters
Process connection: universal flange
Process temperature: -40~130℃ (standard type) / -40~250℃ (high temperature type)
Process pressure: -0.1~4.0 MPa (flat flange) -0.1~0.3 MPa (universal flange)
Accuracy: ±15mm
Protection level: IP67

SIRD-904 Radar Level Gauge with Parabolic Antenna

Application: solid materials, strong dust, easy to crystallize, condensation occasions
Measuring range: 80 meters
Process connection: threaded, universal flange
Process temperature: -40~130℃ (standard type) / -40~250℃ (high temperature type)
Process pressure: -0.1~0.3MPa
Accuracy: ±15mm
Protection level: IP67

SIRD-905 Horn Antenna Radar Tank Level Sensor

Application: solid particles, powder
Measuring range: liquid 35 meters / solid block 20 meters / solid powder 15 meters
Process connection: thread, flange
Process temperature: -40~130℃ (standard type) / -40~250℃ (high temperature type)
Process pressure: -0.1~4.0 MPa (flat flange) -0.1~0.3 MPa (universal flange)
Accuracy: ±15mm
Protection level: IP67

SIRD-804 Radar Solid Level Sensor

Applicable medium: solid particles or blocks, not suitable for solid powder
Application: Lime block measurement; raw coal measurement
Explosion-proof certification: Exia IIC T6 Ga/ Exd IIC T6 Gb
Measuring range: 35m
Antenna: Horn antenna
Frequency: 6 GHz
Process temperature: -40~130℃(standard type)/-40~250℃(high-temperature type)

SIRD-806 Radar High Temperature Level Sensor

Applicable medium: solid, especially medium measurement in a high-temperature environment
Application: Blast furnace level measurement
Explosion-proof certification: Exia IIC T6 Ga/Exd IIC T6 Gb
Measuring range: 15m
Antenna: Horn antenna
Frequency: 6 GHz
Process temperature: (-40~400)℃

What is the difference between Ultrasonic Level Sensor and Radar Level Sensor?

Ultrasonic Level Sensor and Radar Level Sensor are non-contact liquid level measuring instruments. As the name suggests, one uses ultrasonic waves and the other uses electromagnetic waves. In addition, what are the differences between ultrasonic level sensors and radar level sensors?

Simply put:

  1. The relative price of Radar Level Sensor is relatively high;
  2. Radar Level Sensor has higher accuracy than ultrasonic;
  3. The measuring range of radar is larger than that of ultrasonic;
  4. When using Radar Level Sensor, consider the dielectric constant of the medium.
  5. Radar Level Sensor has horn type, rod type and cable type. Compared with ultrasonic, it can be applied to more complicated working conditions;
  6. Ultrasonic cannot be applied to working conditions such as vacuum, high steam content or foam on the liquid surface.

Extended Reading: FMCW Radar for High Temperature Level Sensor

Ultrasonic liquid level sensors are non contact level measurement devices. In the measurement, the ultrasonic pulse is sent by the sensor (transducer). The sound wave is reflected by the liquid surface and received by the same sensor or ultrasonic receiver. It is converted into an electrical signal by a piezoelectric crystal or a magnetostrictive device. It is transmitted and received by the sound wave. The time between the sensor and the surface of the liquid being measured. Due to non-contact measurement, the measured medium is almost unlimited. It can be widely used for measuring the height of various liquid and solid materials. Like: water level, fuel level, oil level, petrol tank level, and so on.

Extended reading: GWR Solid Level Sensor-Cement silo-Ash powder measure

Guided wave radar level transmitter uses guided wave radar (GWR) technology. Based on the reflection of microwave on the surface medium. Through the probe, continuous level measurement of liquid and solid levels is completed.

A guided wave radar level transmitter is also called a wave-guided radar level sensor. They can measure both levels and the interface between two media. Through probe rod or cable, complete level contact types continuous level measurement. Such as Coaxial Probe Guided Wave Radar Level Transmitter. This is different from ultrasonic level measurement, which is a non-contact measurement. A guided wave radar level transmitter is often used for tank level measurement. Including liquid and solid. Output 4~20mA/HART, so as to measure and control the level during production.

Extended reading: GWR Solid Level Sensor-for Cement silo-Ash powder measure

Radar Level Sensor Price

The price of the radar level sensor is related to the medium, installation method, and pressure level.

  1. The medium is divided into ordinary type and anti-corrosion type. The cost of the ordinary type is relatively low, and the price of the anti-corrosion type is relatively expensive.
  2. The pressure levels are divided into 1.0MPA, 1.6MPA, 2.5MPA, 4.0MPA, 25MPA. The greater the pressure, the more expensive the price. So the pressure is directly proportional to the price.
  3. Every customer who has bought a radar level sensor knows that the installation method is different. Top-mounted and side-mounted. Because of the different structure, the top-mounted type is more expensive than the side-mounted type.

Sino-Inst provides customers with the most reasonable prices on the basis of ensuring product quality. Radar Level Sensor Price reference range: USD500-1500.00/pc

Extended reading: ​Solid flow meter | For bulk solids-powder-soybean-cement 

Featured Radar Water Level Sensors

Frequently
Asked
Questions

Radar level measurement adopts the transmitting-reflection-receiving working mode. The antenna of the radar level sensor emits electromagnetic waves. These waves are reflected by the surface of the measured object. It is received by the antenna. The time from emission to reception of electromagnetic waves is proportional to the distance to the liquid surface. The radar level gauge records the elapsed time of the pulse wave. The transmission speed of electromagnetic waves is constant. The distance from the liquid surface to the radar antenna can be calculated. Thereby know the liquid level of the liquid surface.

A liquid level sensor is an instrument for measuring the height of a liquid and converting it to an electrical signal. The liquid level signal output can then be utilized by other instrumentation to display, monitor, log or control the liquid level.

The Water level sensor mainly has contact type and non-contact type. Different water level sensors have different working principles.
1. The first type is contact. Including single flange static pressure / double flange differential pressure liquid level transmitter, float type liquid level transmitter, magnetic liquid level transmitter, input type liquid level transmitter, electric inner float level transmission Devices, electric float level transmitters, capacitive level transmitters, magnetostrictive level transmitters, service level transmitters, etc.
2. The second type is non-contact. Divided into ultrasonic liquid level transmitter, radar liquid level transmitter, etc.

Sino-Inst offers over 10 Microwave Radar Liquid Level Sensors for level measurement. About 50% of these are Radar level meters, 40% is the tank level sensor.

A wide variety of Microwave Radar Liquid Level Sensors options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of radar level measurement instrumentation, located in China.

Request a Quote

Please enable JavaScript in your browser to submit the form

SIRD-902 Drop Antenna Radar Tank Level Sensor

The working frequency band of Radar Tank Level Sensor is 24G~26GHZ. Radar Tank Level Sensor is a non-contact radar transmitter based on the principle of FM continuous wave.

SIRD-902 Drop antenna Radar Tank Level Sensor is an integral PTFE drop antenna type radar level sensor. It is used to measure the distance and level of strongly corrosive liquids, pastes and solid media. Compared with the radar level sensor that adopts the pulse measurement principle, it can measure stably, reliably and with high precision even in dusty, foamy, and highly corrosive applications. Compared with pulse radar or GWR, there are many features they don’t have.

Sino-Inst offers a variety of Radar Level Sensors for industrial level measurement. If you have any questions, please contact our sales engineers.

Features of SIRD-902 Drop Antenna Radar Tank Level Sensor

  • Non-contact measurement;
  • 4-20mA standard output;
  • HART bus communication;
  • K band, high precision, high reliability;
  • Solve the measurement problems of liquid, slurry, paste and other stirring, foam or liquid level fluctuation and violent stirring;
  • The drop-type antenna can be used in harsh working conditions such as severe condensation or strong corrosive media.

Specifications of SIRD-902 Drop Antenna Radar Tank Level Sensor

Application:Temperature, pressure, slightly corrosive liquid;
Storage container, process container or agitating occasion with severe fluctuation; occasions with severe condensation or strong corrosive medium
Measuring Range:30 meters
Process Connection:Thread, flange
Process  Temperature:-40~130℃(standard type) /
-40~250℃(high-temperature type)
Process Pressure:-0.1~4.0MPa
Accuracy:±3mm
Protection Grade:IP67
Frequency Range:26GHz
Supply:Two-wire system (DC24V) / Four-wire system (DC24V/AC220V)
Signal Output:Exia ⅡC T6 Ga / Exd IIC T6 Gb
Outer Covering:Aluminum
Single Chamber / Aluminum
Dual Chamber / Plastic / Stainless Steel Single Chamber
Explosion-proof Grade:4…20mA/HART (two-wire/four-wire) / RS485 Mod bus
Antenna MaterialStainless Steel  /  PTFE

Radar Level Sensor Application

SIRD-902 Drop Antenna Radar Tank Level Sensor is equipped with a drop antenna.

The water drop antenna is also called a spherical antenna.

This antenna has strong signal processing capabilities. Not only can measure liquid media. It can also measure slurry media. It is used to measure the distance and level of strongly corrosive liquids, pastes and solid media.

Others Radar Level Sensor Applications

  1. The steel industry

Production processes:
Coal coking: coal storage bins, coking bins, gas tanks, coal tar and crude benzene tanks
Sintering plant: sintering material mixing silo, cold return ore, pellet silo
Ironworks: intermediate warehouse for ironmaking, blast furnace material level, etc.

Working condition characteristics:
Solid material measurement, strong dust, low dielectric constant, long range.
Volatile crystals of tar and crude benzene
High temperature and dust adhesion of blast furnace material level

Selection application:
The solid measurement is mainly based on high-frequency pulse radar level meter.
Guided wave radar level gauges can be used for crude benzene and coal tar.

  1. Coal industry

Production processes:
Raw coal bunker, pulverized coal bunker, coal gangue storage material level, coal washing pool.

Working condition characteristics:
Typical solid material measurement, strong dust, low dielectric constant, long range.

Selection and application:
The high-frequency pulse radar level meter is mainly used.

  1. Cement industry Production processes:
    Raw material warehouse, raw meal homogenization warehouse, clinker warehouse, finished product warehouse, fly ash warehouse, raw coal warehouse, gypsum warehouse, cement slag warehouse Working condition characteristics:
    Typical solid material measurement, strong dust, low dielectric constant, long range. Selection application:
    The high-frequency pulse radar level meter is mainly used.
  2. Power industry Thermal power, hydropower, and biological power generation

Production processes:
(Thermal power) raw coal and pulverized coal silo, circulating pool, low-elevation water level, limestone powder silo, ash hopper level, ash silo, slag silo, desulfurization tower liquid level

Working condition characteristics:
Solid material measurement, strong dust, low dielectric constant, long range.
Low water level. High temperature and high pressure;
Desulfurization tower liquid level foam, water vapor, crystallization, spray interference, side installation

Selection application:
The measurement of solid materials is based on high-frequency pulse radar level meters.
Guided wave radar for high and low water level applications;
Low-frequency radar level meters are commonly used for liquid level in desulfurization towers.

  1. Non-ferrous metallurgy industry: aluminum, nickel, zinc, and titanium industries

Production processes:
(Aluminum) slurry tank, dissolution tank, flash tank, post-dissolution tank, flocculation tank, settling tank, decomposition tank, alumina powder silo

Working condition characteristics:
Various chemical reaction environments have high temperature, strong water vapor, stirring or corrosion factors

Selection application:
In view of the influence of high-temperature water vapor, refer to factors such as corrosion, range, stirring, hanging material, etc.
Choose guided wave radar or low-frequency radar level meter.
High-frequency radar level meters are still preferred for solid measurement.

  1. Water conservancy industry

Application range:
Hydrological monitoring, flood control alarm, farmland irrigation

Working condition characteristics:
The signal transmission is far, the power supply voltage is low, and the installation location is affected by the river embankment and dam. The radar wave with a small beam angle is preferred

Selection application:
Choose high frequency radar level meter with MODBUS protocol

  1. Food and medicine industry

Production processes:
Edible oil tank, soybean meal storage tank

Working condition characteristics:
The tank environment is simple, or has accuracy requirements, and antenna hygiene requirements in the pharmaceutical and food industries

Selection application:
A high-precision measurement environment gives priority to high-frequency radar level meter
If there are sanitary requirements, an antenna with a sealed material that meets sanitary conditions should be selected

  1. Industrial petrochemical industry, coal chemical industry

Production processes:
Petrochemical industry: crude oil storage, gasoline tank, diesel tank, natural gas tank, etc.

Coal coke chemical industry: refer to the coal industry

Calcium carbide chemical industry: coal bunker, calcium carbide bunker, etc.

Working condition characteristics:
Solid material measurement, strong dust, low dielectric constant, long-range.
The measurement environment of various oil depots is simple, and accuracy requirements may be required
There is pressure in the natural gas spherical tank, and the dielectric constant is small
Oscillation interference echo exists in gas tank level measurement
Various chemical reactor conditions are different

Selection application:
The measurement of solid materials is based on high-frequency pulse radar level meters.
For various oil depots with precision requirements, high frequency radar is preferred for spherical tanks
Gas tanks that are prone to oscillating interference signals also have a limited choice of high-frequency radars
Selection of chemical reactor according to actual conditions and parameters

  1. Environmental protection and water treatment industry

Processing link:
Collection wells, coarse grids, fine grids, biochemical reaction tanks, mud flushing tanks, sludge tanks, well-dissolved medicine tanks

Working condition characteristics:
Except for the ultra-long range and narrow space such as collection wells, other environments are relatively simple

Selection application:
Guided wave radar or high-frequency radar level meter can be selected for collecting wells according to the range requirements. Generally, ultrasonic level meters are more commonly used in simple environments.

  1. Semiconductor industry

Production link: Silica powder warehouse

Working condition characteristics: very low dielectric constant, strong dust

Selection application: high frequency radar level meter

Extended reading: FMCW Radar Level Transmitter 120GHz

Radar Antenna Types

Radar Antenna Types
  1. Horn antenna for radar level gauge:
    26G high-frequency radar-type level measuring instrument. Output 4-20mA analog signal. The maximum measuring distance can reach 70 meters. This antenna has been further optimized. The new and fast microprocessor can perform higher-speed signal analysis and processing. The instrument can be used for particularly complex measurement conditions in reactors or solid silos.
  2. Rod antenna for radar level gauge:
    Suitable for measuring liquids. Corrosive media. The maximum measuring distance can reach 20 meters. The antenna is further optimized. The new and fast microprocessor can perform higher rate signal analysis and processing. The instrument can be used for very complex measurement conditions in the reactor or solid silo.
  3. Parabolic antenna for radar level gauge:
    This is a new type of antenna launched in China. It is mostly used in high-frequency transmitting radars. It is especially suitable for measuring targets and avoiding obstacles. 26G high frequency radar type level measuring instrument. Output 4~20mA analog signal. The maximum measuring distance can reach 70 meters. The antenna is further optimized. The new and fast microprocessor can perform higher rate signal analysis and processing. The instrument can be used for very complex measurement conditions in the reactor or solid silo.
  4. Radar level gauge casing antenna:
    The casing has a focusing effect on radar waves. Therefore, when the dielectric constant is small or the liquid level produces continuous eddy currents or the device in the container causes false reflections, this type of instrument is suitable. But the measured medium is required to have good fluidity. It is not easy to hang the material.
  5. Lens radar liquid level antenna:
    Transmits narrow microwave pulses and transmits downward through the antenna. The maximum measuring distance can reach 70 meters. The antenna is further optimized. The new and fast microprocessor can carry out higher-speed signal analysis and processing. The instrument can be used for some complex measurement conditions such as reactors and solid silos.

The above content is for your reference only. When choosing the antenna of the radar level gauge, you should choose according to the actual needs of the measurement environment.

Extended reading: Magnetostrictive Hydraulic Cylinder Position Sensor

Radar Tank Level Sensor Working Principle

Frequency Modulated Continuous Wave Technology (FMCW)

The drop-type antenna emits radar waves, which are received by the antenna after being reflected on the surface of the medium. The radar principle used is Frequency Modulated Continuous Wave (FMCW). The frequency modulated continuous wave (FMCW) radar sends out a signal in the high-frequency band. Within its measurement range, the frequency of the radar wave increases linearly (called frequency sweep).

The transmission and reception of radar waves correspond to a time difference t. The distance d between the radar and the surface of the medium conforms to the formula t=2×d/c. Where c is the transmission speed of the radar wave above the surface of the medium, that is, the speed of light.

SIRD-902 Drop Antenna Radar Tank Level Sensor performs signal processing by comparing the frequency difference between the reflected wave and the current transmitted wave. The frequency difference △f is proportional to the distance, and the greater the frequency difference, the greater the distance.

After Fast Fourier Transform (FFT), the frequency difference Δf is converted into a frequency spectrum, and the distance d is calculated from this. The height of the level is calculated by the given tank height.

Extended reading: Radar Level Meter for Corrosive Liquids

Advantages

  • Measurement is not affected by temperature, pressure, or dust
  • User-friendly adjustment saves time
  • Non-contact, continuous level measurement over larger ranges
  • Unaffected by sludge and biomass, dust, foam, oil, grease and other coatings, uneven surfaces, turbulence, pressure, and vacuum
  • Single-frequency radar level sensors for liquid sensing, dual-frequency radar level sensors for level measurement of aggregates, gravel, sand, coal, asphalt, and other solids
  • Simple mounting and push-button calibration

Disadvantages

  • Very sensitive to build-up on the sensor surface.
  • They are very expensive. Price increases with accuracy.

Extended Reading: Dielectric constant for radar level transmitter

Because the general test distance of radar level gauges is mostly 2-10m or more than 10m. It is difficult to simulate the distance required for calibration in the laboratory. Therefore, radar level gauges mostly use online calibration.

The online calibration of the radar level gauge utilizes the on-site process conditions. Through the change of the liquid level, the output value of the radar level gauge is compared with the actual gauge measurement value or other forms of liquid level measurement value.

According to the “Measurement and Verification Regulations for Level Gauges”, the radar level gauge is calibrated at multiple points or single points. Then it is debugged through the debugging software to make it meet the measurement accuracy requirements.

The conventional online calibration method of the radar level gauge can ensure that it is carried out in accordance with the requirements of the regulations. At the same time, the online calibration will calibrate the process interference and installation error factors at the same time. Therefore, the actual measurement accuracy of the radar level gauge is higher than that of the laboratory calibration.
However, on-line routine calibration must use on-site process conditions. During the calibration period, on-site process equipment-storage tanks or reaction tanks must be shut down, which seriously affects on-site process production.

At the same time, the on-site liquid level change is affected by the process conditions, and the stabilization time is too long. Therefore, the online routine calibration time is usually longer. Gauge measurement or other forms of liquid level measurement are also restricted by on-site safety and technical influences.

Extended Reading: Guided-wave radar (GWR) level transmitter working principle

Radar Level Sensor is an advanced measuring instrument. It is suitable for solid materials, process containers or strong dusts that are easy to crystallize and dew. It has the advantages of low maintenance, high performance, high precision, high reliability and long service life. It can adapt to harsh production environments such as high temperature, high pressure, and steam.

For powdery materials, especially for the measurement of pneumatically conveyed powdery materials:

Although dust has no effect on radar in theory, a large amount of dust can also scatter and affect echo. Cable guided wave radar can be selected.

Because the microwave is transmitted in the steel cable, the dust generated during the transportation of the material has no effect on the measurement.

Cable guided wave radar can be used for the concentrate, quartz, and pulverized coal of the flash furnace, and the measurement effect is good.

For the measurement of granular or bulk materials:

The guided wave cable of the guided wave radar is easily damaged by hard materials. This problem is encountered in the level measurement of the limestone silo.

A high-frequency Radar Level Sensor must be selected. The smaller the emission angle of the microwave, the better. Because the higher the frequency of the microwave, the shorter the wavelength of the microwave. To ensure that the emitted radar wave can be reflected back to the radar to the greatest extent on the rough solid surface Probe. The smaller the emission angle, the smaller the probability of forming clutter and diffuse emission.

The high frequency Radar Level Sensor is adopted because of its small launch angle and good echo signal. Using continuous frequency modulation technology, the anti-interference ability is greatly improved. Solid and even pneumatically transmitted powders can also be accurately measured.

Extended Reading: GWR Level Sensor for High Temperature & High Pressure

Radar level meter: Very short microwave pulses with very low transmit energy are transmitted and received through the antenna system. Radar waves travel at the speed of light. The running time can be converted into a level signal by electronic components. A special time extension method can ensure stable and accurate measurement in a very short time.

Ultrasonic liquid level meter: The high-frequency pulse sound wave emitted by the ultrasonic transducer (probe) meets the surface of the measured level (material). The reflected echo is received by the transducer and converted into an electrical signal.

Read more about: Ultrasonic VS Radar level transmitter-different applications

From the above two principles, we can see the following two differences:

  1. The radar level meter emits electromagnetic waves. The wave speed has nothing to do with ambient temperature, smoke, pressure, etc. It is the same even in a vacuum. The propagation speed is always the speed of light.
  2. Ultrasonic liquid level meter emits ultrasonic waves, which belong to mechanical waves. Like sound waves, its propagation speed is closely related to the state of the propagation medium. Ultrasonic liquid level meter is used to measure the liquid level of atmospheric vessels. The probe contains temperature measuring elements to compensate the temperature of the wave speed. Because of the material, the temperature range used is relatively not very wide.

From the difference between the above 2 points of liquid level meter, the following 2 application conclusions can be summarized:

  1. Ultrasonic is mostly used for meteor measurement, and radar is mostly used for liquid level measurement;
  2. In terms of energy, the emitted wave of radar is larger than that of ultrasonic waves. Electromagnetic waves have a stronger transmission distance and speed than mechanical waves. However, electromagnetic waves are susceptible to electromagnetic interference. Mechanical waves are easily attenuated by gaseous substances.
    So its application is to detect the place where the ultrasonic gas must be opened and the gas phase is relatively clean air. Compared with the radar, it can be resealed and used in a small amount of vapor phase volatilization. But this thing is ideal when the gas phase is in the atmosphere, otherwise the maintenance amount will be increased.

Extended reading: Industrial Tank level indicators and Tank Level Gauges

Pulse Radar Level Transmitter is a transmitter that generates a 6.3 GHz pulse from the microprocessor control circuit and transmits it through the surface of the sensor.

Due to the strong penetrating power of the pulse radar, some foam, smoke, water vapor, etc. that usually interfere with the ultrasonic level gauge do not have any interference to the pulse radar level gauge.

Extended Reading: Types of Level Transmitters:

Guided Wave Radar Level Sensor for Liquid and Bulk Solids Contact level measurement.

Guided wave radar is a measuring instrument based on the principle of time travel. The radar wave runs at the speed of light. The operating time can be converted into level signals by electronic components. The probe emits high-frequency pulses and propagates along the cable or rod probe. When the pulse meets the surface of the material, it is reflected back and received by the receiver in the instrument. And convert the distance signal into level signal. SIRD-701 Guided Wave Radar Level Sensor is suitable for liquid and Bulk Solids measurement, and complex process conditions.

Extended reading: GWR Solid Level Sensor-for Cement silo-Ash powder measure

More Featured Radar Level Sensors

Level Senors for Tank Level Measurement

Tank level senor is a level sensor used to measure the tank level. The liquid level is the level of the liquid in a sealed container (such as a water tank) or an open container (water tank). The instrument that measures the liquid level is called a liquid level sensor, a liquid level gauge or a liquid level transmitter. The liquid level sensor is a kind of level instrument.

Hydrostatic, Ultrasonic, Magnetostrictive, Radar, Differential Pressure are commonly choices for tank level measurement. Liquid level sensors have been around for decades for leak detection or level measurement. Common measured mediums are: Water, Fuel, Diesel, Gasoline, diesel, liquefied gas, liquid ammonia, etc.

Read more about: 7 Level Senors for Tank Level Measurement

FAQ

♦ Radar level meter: stainless steel horn antenna. It is more suitable for the site with relatively clean working conditions and no volatile behavior.
♦ Radar level meter: stainless steel horn and PTFE cover antenna. Suitable for working conditions with volatile matter and dust on site.
♦ Radar level meter: all plastic antenna with PTFE cover antenna. Suitable for working conditions with volatile matter, dust and condensation on site.
♦ Radar level meter: stainless steel horn with purge antenna. It is more suitable for working conditions that easily cause pollution to the antenna.
♦ Radar level meter: With extension pipe and radiating pipe, it can be used in ultra-high temperature conditions (such as molten steel). It is more suitable for converters, blast furnace loading positions and raw material warehouses in the metallurgical industry. If the dust in the site is relatively large and there is water vapor in the ore powder, try to use a high-frequency radar level meter when using it.

Common liquid level sensors are:
Float type liquid level sensor, magnetostrictive liquid level sensor,
Capacitive liquid level sensor, resistance liquid level sensor,
Radar level sensor, laser level sensor,
Ultrasonic liquid level sensor, pressure sensor,
Bubble level sensor, isotope level sensor,
Thermodynamic liquid level sensor
There’re 7 main types of level transmitters that Sino-Instroffers. Each type of transmitter works in a different way and makes it useful for different types of processes.
Extended reading: Float Level Sensors – Single and Multipoint

Generally speaking, we have the following two-division methods for the types of radar level sensors.
1. There are two types of radar level sensors: contact and non-contact.
Also known as: Noninvasive or Invasive.
The non-contact type includes pulse radar and continuous frequency modulation. The probe is usually a horn antenna, that is, a tubular antenna, but the diameter of the horn is different, and the length of the horn is different. So it looks like some speakers, and some look like tubes, but they are actually one.
In addition, the contact radar is equipped with a rod antenna, usually called a guided wave radar, which is a pulse radar in principle. You can also learn more about guided wave radar level sensors.

2. In principle, radar level sensors can be divided into three main types: Pulsed. Frequency modulated continuous wave. And guided wave radar.
Non-contact radar is called a radar level sensor, which includes two types of rod antenna and horn.The contact radar level gauge can also be called a guided wave radar level gauge. Including single rod type and single cable type, double cable type, coaxial type, etc., which includes high-frequency and low-frequency radar level gauge.

Extended reading: Radar Liquid Level Sensor|Corrosive, steam, volatile liquids

There are many types of water level sensors. Including single flange static pressure / double flange differential pressure water level sensor, float type water level sensor, magnetic water level sensor, input type water level sensor, electric inner float water level sensor, electric float level sensor, capacitive water level sensor, magnetostrictive Water level sensor, servo water level sensor, etc., ultrasonic water level sensor, radar water level sensor, etc. It can be divided into contact type and non-contact type.
Extended reading: Ultrasonic level transmitter for Hazardous

Sino-Inst offers over 10 Radar Tank Level Sensors for level measurement. About 50% of these are Radar level meters, 40% is the tank level sensor.

A wide variety of Radar Tank Level Sensors options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of radar level measurement instrumentation, located in China.

Request a Quote

Please enable JavaScript in your browser to submit the form

SI-FMF21 FMCW Radar Silo Level Sensor

Silo Level Sensor is specially used for level measurement of solid material silos (including fine ore silos). Perfect Solutions for Silo Level Monitoring and Control.

SI-FMF21 FMCW Radar Silo Level Sensor adopts 120GHz FM continuous wave technology, 10GHz sweep bandwidth, and has electromagnetic characteristics in the terahertz band. It has the ability to penetrate materials with small dielectric constant. In a strong adhesion and strong dust environment, the measurement is stable without interference and does not require any purge device. The measuring distance can reach 150 meters. Perfect solutions in continuous level measurement and remote inventory management systems.Like the storage of powders & bulk solids in bins, silos, vessels, etc.

Sino-Inst offers a variety of FMCW Radar Silo Level Sensors for industrial level measurement. If you have any questions, please contact our sales engineers.

Features of SI-FMF21 FMCW Radar Silo Level Sensor

  • The 120GHz frequency modulated continuous wave radar level meter only needs 80ms to complete a complete measurement and calculation process for a distance of 100m. This allows the system to have more time and resources to deal with all kinds of things in meter level applications. For example: probability evaluation/prediction/credibility analysis/input/output/communication, etc.
  • The PTFE lens antenna is fully enclosed and potted. It solves the structural treatment of the antenna near-field radiation suppression. This makes it have good directional performance. The beam angle is controlled within 1 degree. The manufacturing process difference of batch products , The deviation may be about ±0.3 degrees.
  • The 120GHz frequency modulated radar level gauge is especially suitable for high temperature, high pressure or high dust, and multiple agitated spaces. It meets many measurement requirements that require a large range and high precision.
  • Evaporation and dust will not affect the measurement;
  • Level measurement of corrosive liquid, no contact, no corrosion-stable measurement;
  • Liquid level measurement of foam and strong dust;

Specifications of SI-FMF21 FMCW Radar Silo Level Sensor

Measuring medium:Liquid
Measuring range:0.3m~150m 
Process connection:Flange≥DN80
Process temperature:-40~110℃
Process pressure:-0.1~0.3 MPa
Accuracy:±5mm         
Protection level:IP67
Frequency Range:123GHz
power supply:Two-wire system (DC24V)/four-wire system (DC12V~24V)/four-wire system (AC220V)
Explosion-proof grade:Exia ⅡC T6 Ga / Exd IIC T6 Gb
Housing:Aluminum/plastic/stainless steel
Signal output:Two-wire system 4…20mA/HART protocol Four-wire system 4…20mA/RS485 Mod bus

Radar Silo Level Sensor Applicaitons

Radar Silo Level Sensor is suitable for high temperature and high-pressure reactor, super large storage tank, and still tube measurement.

Radar Silo Level Sensor is suitable for high-precision metrological measurement and perspective measurement.

Radar Silo Level Sensor is suitable for extremely harsh working conditions such as strong dust and steam, and storage tanks with special processes such as stirring and heating rods.

  • Chemical industry
  • Torpedo car
  • Liquefied petroleum gas
  • Coal
  • Food and grains
  • Bulk materials
  • Cement
  • Coke

Extended reading: GWR Solid Level Sensor-for Cement silo-Ash powder measure

Solutions for Silo Level Monitoring and Control

Cement Silo Level Indicator

Cement industry material process storage level detection. Including clinker warehouse, raw meal homogenization warehouse, raw material mixing warehouse, limestone storage warehouse, raw coal warehouse and cement mixing warehouse, etc.

The cement silo (tank) is not a simple silo. It also contains many auxiliary devices. Such as arch breaking device, dust collector, level gauge, pressure safety valve and so on.
Today, I will mainly explain to you: the main functions and characteristics of the cement silo (tank) level sensor:

Extended reading: Radar level sensor for solids – Dust solid level measurement

First, the cement silo (tank) liquid level sensor is a sensor used to detect the height change of the material in the container. It can continuously detect the height, volume and other values ​​of the material, and transmit the relevant information to the computer or display instrument.

Secondly, the cement tank liquid level sensor is mainly used to automatically detect and control the limit material level of various materials (such as powder, granules or blocks). Different types of material straightening machines can meet the requirements of different working conditions.

Furthermore, in the concrete mixing equipment, the cement tank is a closed storage device. The user cannot intuitively understand the amount of powder in it, and a liquid level sensor is needed at this time.
The liquid level sensor in the cement tank can accurately record the position of the material in the cement tank for easy management.

Lime Silo Level Sensor

As a multifunctional product, lime is not only used to purify raw materials, but also often used to clean and neutralize waste water from sugar beets. The resulting by-products are also useful because it contains a mixture of lime and organic residues. They are usually reused as soil additives and conditioners in agriculture and are rich in organic matter.

Most sugar processing plants have their own lime kilns, which require good high-purity limestone to burn. This “high calcium” limestone is converted into quicklime in a lime kiln at a temperature of 900°C. In order to obtain the milk of lime, the “calcined” lime is mixed into the water. In this process, accurate and reliable level measurement can ensure consistent production.

The processing area must have a high level of safety. Because lime is harmful, especially irritating to the skin and eyes. All outer surfaces of the radar level gauge are of plastic or stainless steel construction, with a fully enclosed PTFE antenna system. This means that in this highly alkaline environment, the sensor will have minimal corrosion and a longer service life.

Extended reading: Radar Level Meter for Corrosive Liquids

Featured Silo Level Monitoring Systems

FAQ

What is an ultrasonic level sensor?

Ultrasonic Level Sensing is a low-cost liquid level measurement technology. Ultrasonic Level Sensing sensors and transmitters are used for tank or river level measurement. Ultrasonic Level Sensing does not need to contact the medium, can be continuously measured at, low cost. Therefore, Ultrasonic Level Sensing is very popular among users. Ultrasonic liquid level sensors are available in general and intrinsically safe types. Output 4~20mA standard signal or output the measurement result to the secondary meter through RS-485. Meets the system’s automatic control.

Which sensor is used to detect water level?

The Water level sensor mainly has contact type and non-contact type. Different water level sensors have different working principles.
1. The first type is contact. Including single flange static pressure / double flange differential pressure liquid level transmitter, float type liquid level transmitter, magnetic liquid level transmitter, input type liquid level transmitter, electric inner float level transmission Devices, electric float level transmitters, capacitive level transmitters, magnetostrictive level transmitters, service level transmitters, etc.
2. The second type is non-contact. Divided into an ultrasonic liquid level transmitter, radar liquid level transmitter, etc.

What is the radar level measurement range?

When selecting radar, there is often a misconception that the selected range should be greater than the height of the tank.
In fact, the range marked on the radar maybe its range. The selection also depends on the characteristics of the container, such as the surface of the storage tank is stable or corrugated, and even stirring. The actual material level that the radar level gauge of the same model can measure under different conditions is very different. E+H’s FMR-23lE radar has a range of 20m, but it can measure 20m for liquids on a smooth surface. If it is used on a buffer tank without stirring and ripples, it can only measure 10m. When it is used to measure the material level with stirring of more than ten meters, the low material level is often not measured. This is actually the selection range is not enough, the problem is solved after increasing the range. Similarly, the dielectric constant of the medium is also easy to be ignored, and attention should be paid to the medium with a small dielectric constant.

Request a Quote

Please enable JavaScript in your browser to submit the form

Bimetallic Thermometer—-WSS Series

Bimetallic thermometer is a kind of field testing instrument for measuring low and medium temperature. It is used especially in industry.

It can directly measure the temperature of the liquid, vapor and gas within -80℃~+500℃ in a variety of production processes. The bimetallic thermometer is made of a metal sheet which is made into a ring and bend shape. When one end is heated and expanded, it will lead to the rotation of the pointer and the working instrument will show the temperature value of the thermal electric potential.

Sino-Inst offers a variety of bimetallic thermometer for industrial level measurement. If you have any questions, please contact our sales engineers.

How Does a Bimetallic Thermometer Work?

The working principle of bimetallic thermometer depends on the two fundamental properties of the metal.The metal has the property of thermal expansion, i.e., the metal expand and contract concerning the temperature.The temperature coefficient of all the metal is not same. The expansion or contraction of metals is different at the same temperature.

What Is WSS Series Bimetallic Thermometer And Its Uses?

WSS series bimetallic thermometer is an on-site detection instrument for measuring low and medium temperature. The bimetal thermometer can directly measure the temperature of liquid, steam and gaseous media in the range of -80℃~+500℃ in various production processes.

What Is The Meaning Of Bimetallic?

They are made up of bimetallic strips formed by joining two different metals having different thermal expansion coefficients. Basically, bimetallic strip is a mechanical element which can sense temperature and transform it into a mechanical displacement. This mechanical action from the bimetallic strip can be used to activate a switching mechanism for getting electronic output. Also it can be attached to the pointer of a measuring instrument or a position indicator. Various techniques such as riveting, bolting, fastening can be used to bond two layers of diverse metals in a bimetallic strip. However the most commonly used method is welding. Since two metals are employed to construct a bimetallic strip, hence they are named so.

Read more about Thermometer

Characteristics

  1. It can display the temperature on-site, which is intuitive and convenient;
  2. It is safe and reliable with long service life;
  3. With a variety of structural forms, which can meet different requirements.

Main Technical Parameters

  • 1.Product implementation standard:JB/T8803-1998
  • 2.Nominal diameter of dial:60,100,150
  • 3.Precision grade:(1.0),1.5
  • 4.Thermal response time:≤40s
  • 5.Protection level:IP55
  • 6.Angle adjustment error Angle adjustment error should not more than 10% of the range
  • 7. Return difference: the return difference of the thermometer should not be more than the absolute value of the error limitation.
  • 8. Repeatability: the repeatability of the thermometer should be no greater than 1/2 of the absolute value of the basic error limitation.

Classification

According to the connection direction of the bimetal thermometer dial and the protective tube, the bimetal thermometer can be divided into four types: axial type, radial type, 135°direction type and universal type.

  1. Axial bimetal thermometer: The pointer plate is connected vertically to the protection tube.
  2. Radial type bimetal thermometer: The pointer disc is connected in parallel with the protection tube.
  3. 135°direction bimetallic thermometer: the pointer disc and the protection tube are connected at 135°.
  4. Universal bimetal thermometer: The connection angle between the pointer plate and the protective tube can be adjusted arbitrarily.
135°type

WSS-420 WSS-520 WSS-421 WSS-521 WSS-422 WSS-522 WSS-432 WSS-532 WSS-424 WSS-524 WSS-425 WSS-525 WSS-526

Axial type

WSS-300 WSS-400 WSS-500 WSS-301 WSS-401 WSS-501 WSS-302 WSS-402 WSS-502 WSS-303 WSS-403 WSS-503 WSS-304 WSS-404 WSS-504 WSS-305 WSS-405 WSS-505 WSS-306 WSS-406 WSS-506

Radial type

WSS-310 WSS-410 WSS-510 WSS-311 WSS-411 WSS-511 WSS-312 WSS-412 WSS-512 WSS-313 WSS-413 WSS-513 WSS-314 WSS-414 WSS-514 WSS-315 WSS-415 WSS-515 WSS-316 WSS-416 WSS-516

Universal type

WSS-480 WSS-580 WSS-481 WSS-581 WSS-482 WSS-582 WSS-483 WSS-583 WSS-484 WSS-584 WSS-485 WSS-585 WSS-586 WSS-486

Installation Requirements

For the installation of bimetal thermometers, attention should be paid to accurate temperature measurement, safety and reliability, and convenient maintenance, and does not affect equipment operation and production operations. The above requirements must be met. When selecting the installation position and insertion depth of the thermal resistance, the following should be paid attention to A few points:

(1) In order to have sufficient heat exchange between the measuring end of the thermal resistance and the measured medium, the location of the measurement point should be selected reasonably and try to avoid installing thermal resistance near the dead corner of the valve, elbow, pipeline and equipment.

(2) The thermal resistance with protective sleeve has heat transfer and heat dissipation loss. In order to reduce the measurement error, the thermocouple and thermal resistance should have sufficient insertion depth:

  • a. For the thermal resistance measuring the temperature of the fluid in the center of the pipeline, the measuring end should generally be inserted into the center of the pipeline (vertical installation or inclined installation). If the pipe diameter of the tested fluid is 200 mm, the insertion depth of the thermal resistance should be 100 mm;
  • b. For temperature measurement of high-temperature, high-pressure and high-speed fluids (such as main steam temperature), in order to reduce the resistance of the protective sleeve to the fluid and prevent the protective sleeve from breaking under the action of the fluid, the shallow insertion method of the protective tube or the hot sleeve type can be adopted Thermal resistance. For shallow plug-in thermal resistance protection sleeves, the depth of insertion into the main steam pipe should not be less than 75mm; the standard insertion depth of thermal-jacket thermal resistance is 100mm;
  • c. If you need to measure the temperature of the flue gas in the flue, even though the flue diameter is 4m, the thermal resistance insertion depth is 1m;
  • d. When the insertion depth of the measuring original exceeds 1m, it should be installed vertically as much as possible, or a support frame and protective sleeve should be installed.

Request a Quote

Please enable JavaScript in your browser to submit the form

What Is Thermal Resistance

What Is Thermal Resistance?

Thermal resistance is one of the most commonly used temperature detectors in medium and low temperature regions.

Thermal resistance thermometry is based on the characteristic that the resistance value of metal conductors increases with temperature. Its main features are high measurement accuracy and stable performance.

Among them, the measurement accuracy of platinum thermal resistance is the highest. It is not only widely used in industrial temperature measurement, but also made into a standard benchmark.

Thermal resistances are mostly made of pure metal materials. The most widely used are platinum and copper. In addition, materials such as nickel, manganese and rhodium have been used to manufacture thermal resistances.

There are many types of temperature-sensing materials commonly used in metal thermal resistors, and platinum wire is the most commonly used.

In addition to platinum wire, metal thermal resistance materials for industrial measurement include copper, nickel, iron, iron-nickel, etc.

Features of Thermal Resistance

  • Stable physical and chemical properties, high measurement accuracy, corrosion resistance and long service life.
  • The temperature coefficient of resistance should be large, that is, the sensitivity should be high.
  • The resistivity should be high to make the thermal resistance smaller and reduce the time constant of temperature measurement.
  • The heat capacity should be small, so that the thermal inertia of the resistor body is small and the response is more sensitive.
  • Good linearity, that is, the relationship between resistance and temperature is linear or a smooth curve.
  • It is easy to process, inexpensive, and reduces manufacturing costs.
  • Good reproducibility, easy for mass production and parts interchange.

Measuring Principle of Thermal Resistance

The temperature measurement principle of thermal resistance is different from that of thermocouple in that thermal resistance measures temperature based on the thermal effect of resistance. That is, the resistance of the resistor body changes with temperature.

Therefore, as long as the resistance change of the temperature-sensing thermal resistance is measured. temperature can be measured. There are mainly two types of metal thermistors and semiconductor thermistors.

The resistance value and temperature of a metal thermal resistor can generally be expressed by the following approximate relationship.
That is, Rt=Rt0[1+α(t-t0)]

where:
Rt is the resistance value at temperature t;
Rt0 is the corresponding resistance value at temperature t0 (usually t0=0℃);
α is the temperature coefficient.

The relationship between the resistance value and temperature of the semiconductor thermistor is: Rt=AeB/t

where Rt is the resistance value when the temperature is t;
A and B are constants that depend on the structure of the semiconductor material.

In comparison, the thermistor has a larger temperature coefficient. The resistance value at room temperature is higher (usually in the thousands of ohms). But the interchangeability is poor and the nonlinearity is serious. The temperature measurement range is only about -50~300℃. It is widely used in temperature detection and control for home appliances and automobiles.

Learn more: Thermal resistance From Wikipedia

Common Types of Thermal Resistance

Platinum thermal resistance is characterized by high measurement accuracy. Good stability and reliable performance.

However, in reducing media, especially at high temperature, it is easily stained and brittle by the steam reduced from the oxide. And change the relationship between resistance and temperature.

In order to overcome the above shortcomings, the thermal resistance core should be installed in a protective sleeve.

Copper thermal resistance is commonly used in industry to measure the temperature in the range of -5O℃~+15O℃.

Copper is easy to purify and is much cheaper than platinum. The temperature coefficient of resistance is large and the relationship is linear. Therefore, when making a thermal resistance with a certain resistance value, compared with platinum, if the length of the resistance wire is the same, the copper resistance wire is very thin, and the mechanical strength is reduced. If the wire diameter is the same, the length will increase many times and the volume will increase.

In addition, copper is easily oxidized above 100°C and has poor corrosion resistance, so the working temperature does not exceed 150°C.

Nickel thermal resistance has a large temperature coefficient and a higher sensitivity than platinum and copper. It is often used to measure temperatures in the range of -60°C to +180°C.

Due to the complicated manufacturing process of nickel thermal resistance, it is difficult to obtain nickel wires with the same α. Therefore, its measurement accuracy is lower than that of platinum thermal resistance. The graduation numbers of standardized thermal resistances currently stipulated in my country are Ni100, Ni300, and Ni500.

The semiconductor spot thermometer is a thermistor made of metal oxides such as manganese, nickel, copper and iron as the temperature measuring element. Its shapes are bead-shaped, round, washer-shaped and sheet-shaped. Commonly used are 61 type bead and miniature bead semiconductor thermistors.

The difference from general thermal resistance is that it has a negative temperature coefficient of resistance. As the temperature increases, the resistance decreases. The range of change is also large, and the temperature coefficient of resistance α reaches -2 to -7%. It is 10 to 100 times larger than metal thermal resistance. Therefore, display instruments with lower accuracy can be used.

Thermal Resistance vs Thermal Conductivity

Thermal conductivity, also known as “thermal conductivity”. [1] is a measure of the thermal conductivity of a material. The symbol is λ or K.
It refers to the heat transferred through the unit horizontal cross-sectional area per unit time when the vertical downward gradient of the temperature is 1°C/m.

Its specific definition is: take two parallel planes with a distance of 1 meter and an area of 1 square meter inside the object perpendicular to the direction of heat conduction. If the temperature difference between the two planes is 1K, it will be conducted from one plane to another within 1 second. The amount of heat is specified as the thermal conductivity of the substance. Its unit is: watt · m-1 · Kai-1 (W · m-1 · K-1).

If there is no heat loss, for a block material with parallel opposite sides, there is
E/t=λA(θ2-θ1)/ι

In the formula, E is the energy transferred in the time t. A is the cross-sectional area. ι is the length. θ2 and θ1 are the temperatures of the two sections, respectively.

In general there are:
dE/dt=-λAdθ/dι

Thermal Resistance Example Problems

TroubleshootingReasonMethod of exclusion
The displayed value of the instrument is lower than the actual value or the displayed value is unstableThere are metal shavings, dust in the protection tube, dirt between the terminals and short circuit of the thermal resistance (water droplets, etc.)Remove metal chips, clean dust, water droplets, etc., find short-circuit points, strengthen insulation, etc.
Display value infinityThe thermal resistance or the lead wire is disconnected and the connection terminal is loosened, etc.Replace the resistor body, or weld and tighten the wiring screws, etc.
There is a change in the relationship between resistance and temperatureThe platinum resistance wire material is corroded and deterioratedReplace the thermal resistance
The display value of the meter is zero or has a negative valueThe thermal resistance wiring is wrong, the thermal resistance is short-circuited, or the cable is short-circuitedCorrect wiring, find short circuit, strengthen insulation, replace resistor body or cable

Temperature Range And Tolerance Level

GraduationTolerance levelWire wound element effective temperaturerangeMembrane element effective temperaturerangeRange of temperature measurement
Pt100AA-50~2500~150±(0.1+0.0017丨t丨 )
Pt100A-100~450-30~300±(0.15+0.002丨t丨 )
Pt100B-196~600-50~500±(0.3+0.005丨t丨 )
Pt100C-196~600-50~600±(0.6+0.01丨t丨 )
Pt100-50~150±(0.3+0.006丨t丨 )
t = temperature Absolute value,units for C

Thermal Resistance With No-fixed Device

WZP-120 WZP -120 2 WZP-120G WZP -120G 2 WZP-121 WZP -121 2 WZP- 121G WZP -121G 2 WZP- 130 WZP -130 2 WZP- 130G WZP -130G 2 WZP- 131 WZP -131 2 WZP- 131G WZP -131G 2 WZC-120G WZC-120 WZC-130 WZC-130G WZC-121 WZC-121G WZC-131 WZC-131G

1) Model 120 and 121 are anti-spring type with the protective grade being IP65; Model 130 and 131 are waterproof type with the protective grade grade being IP55. 2) Protective tube material is 1Cr18Ni9Ti and the rest of the material is ordered according to the agreement.

Fixed Screw Type Thermal Resistance

WZP-220 WZP -220 2 WZP-220G WZP -220G 2 WZP-221 WZP -221 2 WZP- 221G WZP -221G 2 WZP- 230 WZP -230 2 WZP- 230G WZP -230G 2 WZP- 231 WZP -231 2 WZP- 231G WZP -231G 2 WZC-220 WZC-220G WZC-230 WZC-230G WZC-221 WZC-221G WZC-231 WZC-231G

1) Model 220 and 221 are anti-spraying type with the waterproof grade being IP65. model 230 and 231 are waterproof type with the protective grade being IP55. 2) Protective tube material is 1Cr18Ni9Ti and the rest of the material is ordered according to the agreement. 3) Nominal pressure is ≤4.0MPa.

Related Blogs

Guide for Digital Fuel Flow Meter

Digital Fuel Flow Meter is a flow meter dedicated to measuring fuel, diesel, gasoline, and petroleum. Digital Fuel Flow Meter generally has a digital display or signal output. Such as…

The Myth of Ceramic Pressure Sensor

What is a ceramic pressure sensor? Ceramic pressure sensors are sensor diaphragms made of ceramic alumina (Al2O3). Ceramic is a material with high elasticity, corrosion resistance, wear resistance, impact, and…

Water Flow Measurement for Pipes and Open Channels

Water flow measurement is common in both industry and life. You may often hear about the use of electromagnetic flowmeters to measure wastewater. The clamp-on ultrasonic flowmeter measures large water…

Sino-Inst, Manufacuturer for Thermal Resistances, like: Armoured thermocouple, assembly thermocouple, explosion-proof thermocouple, etc.

Sino-Inst’s Thermal Resistances, made in China, Having good Quality, With better price. Our Temperature measurement instruments are widely used in China, India, Pakistan, US, and other countries.

Request a Quote

Please enable JavaScript in your browser to submit the form

SI-FMF15 FMCW Radar for High Temperature Level Sensor

High temperature level sensor is based on FMCW Radar to measure high temperature liquid. Non-contact measurement. The temperature is as high as 240°C. IP67 protection. rs485 output.

High Temperature Level Sensor is also called high temperature molten salt level sensor. Use continuous frequency modulation wave radar to measure. SI-FMF15 FMCW Radar High Temperature Level Sensor is manufactured based on the principle of linear frequency adjustment-radar working. It can ensure the accurate and stable liquid level measurement of the radar in high temperature, high pressure, strong corrosion, strong dust and other environments. High temperature type 240℃, special customization can reach 1200℃.

Sino-Inst offers a variety of FMCW Radar High Temperature Level Sensors for industrial level measurement. If you have any questions, please contact our sales engineers.

Features of SI-FMF15 FMCW Radar High Temperature Level Sensor

  1. Measurement accuracy
    The measurement accuracy of the terahertz frequency-modulated continuous wave radar level meter is ±1mm. Reliable and high-precision measurement. It really reduces the workload of field operators.
  2. Launch angle
    Radar wave emission angle <2°. Even in extremely complex installation environment, it can measure the material level stably and accurately.
  3. Measuring range
    The measurement range of the terahertz FM radar level meter is 0.08m-150m. It has a very small blind area and a large measurement range. It can meet most measurement occasions.
  4. Penetration
    The terahertz frequency-modulated continuous wave radar level gauge is extremely penetrating. According to the dielectric constant of the crystalline medium, it can penetrate the crystalline layer of up to 100mm.
  5. High temperature conditions
    The terahertz FM radar level meter has good penetration performance. For high temperature occasions, thermal insulation accessories such as ceramic or quartz glass can be added to the front end of the antenna. With the special environment learning function, it can measure high temperature liquids.
  6. Strong corrosiveness
    It has good penetration performance. For strong corrosion occasions, the front end of the antenna can be equipped with PTFE or PFA anti-corrosion sheath. And the maximum thickness of 30mm fluoroplastic can be added. It has good pressure resistance while anti-corrosion.
  7. Foam products
    It has good penetration performance. Therefore, it can penetrate the foam up to 1000mm for liquid level measurement. The terahertz frequency modulation radar level gauge can also measure the foam itself.
  8. Sensitivity
    It has three adjustable sensitivity. When high sensitivity is selected, the radar response time is less than 1S.

Specifications of SI-FMF15 FMCW Radar High Temperature Level Sensor

Measuring medium:Liquid
Measuring range:0.1m~120m
Process connection:Flange≥DN80
Process temperature:Standard model -60~130℃;
high temperature model -60~240℃;
special customization -60~1200℃
Process pressure:-0.1~2.5 MPa
Accuracy:±2mm         
Protection level:IP67
Frequency Range:123GHz
power supply:Two-wire system (DC24V)/four-wire system (DC12V~24V)/four-wire system (AC220V)
Explosion-proof grade:Exia ⅡC T6 Ga / Exd IIC T6 Gb
Housing:Aluminum/plastic/stainless steel
Signal output:Two-wire system 4…20mA/HART protocol Four-wire system 4…20mA/RS485 Mod bus

Extended reading: What is Modbus Protocol?

SI-FMF15 FMCW Radar Level Sensor Applicable Medium

  • Level measurement of solids (powders, granules, blocks);
  • Level measurement of plastic particles with low dielectric constant;
  • Liquid level measurement. Reactor liquid level. Large steam level. Foam product level. Crystalline product level. Ultra-high temperature product level. Ultra high pressure product level. Hygienic product level.

Extended reading: Dam water level measurement

Advantages of FM Radar Level Meter

FMCW radar level meter is suitable for various complex working conditions. It can also ensure measurement stability and accuracy in high temperature and high dust environments.

  • Not affected by atmospheric precipitation;
  • Ambient temperature from -60℃;
  • from outside the storage tank;
  • The inner antenna of the terahertz FM continuous wave radar level meter is heated and protected by a fluoroplastic lens
  • The measurement beam is narrow. Easy installation and stable measurement;
  • Level measurement accuracy;
  • Not limited by the temperature in the container;
  • Evaporation and dust do not affect the measurement;
  • Boiling liquid level measurement;
  • Corrosive liquid level measurement. No contact, no corrosion;

FMCW Radar Working Principle

In the early years, a non-contact frequency-modulated continuous wave radar level meter produced by a company in the United States used FMCW technology to perform more accurate level measurement for more complex occasions. This FMCW technology has caused a global sensation. It has made more researchers devote themselves to FMCW technology. FMCW here is frequency modulated continuous wave.

This FMCW radar technology uses a high frequency sweep signal typically 8.5 to 9.9 GHz. The radar signal is sent from one end of the antenna and is received by the receiver after time t. The frequency difference Δf between the transmitting and receiving is converted into the level of the measured medium by the Fourier transform method.

However, with the development of the times and the efforts of scientific researchers, the continuous waves of 26GHz, 28GHz, 80GHz and 120GHz have been derived from the FM continuous wave radar level gauge.

FM continuous wave radar level meter is a general-purpose instrument for measuring coal, cement, grain, alumina, limestone, chemical raw materials and other materials. It is widely used in cement, chemical, environmental protection, electric power, food and other industries.

The 120GHz radar level meter is especially suitable for high temperature, high pressure or high dust, and multi-stirring environments. It meets many measurement requirements that require a large range and high precision.

Terahertz FM CW radar level meter mainly uses triangular FM continuous wave. After the transmitted signal is scattered by the target, it is accepted by the antenna. The delay time τ=2R/c. Among them, R is the distance from the target to the antenna, and c is the propagation speed of the electromagnetic wave. .

When the detection target is stationary, the distance calculation formula is R=(cT/4B)×fb, where T is the period of the triangular wave, and B is the frequency modulation bandwidth.

From the formula R=(cT/4B)×fb, it can be obtained that the frequency fb of the beat frequency signal has a linear relationship with the distance R. Therefore, the key to the ranging system is to measure the frequency of the beat frequency signal.

Under certain conditions of bandwidth B and period T, the distance R can be calculated as long as the frequency fb is obtained. Therefore, the accuracy of frequency measurement directly affects the accuracy of distance measurement.

The difference frequency signal is usually sampled by A/D and then calculated by FFT to obtain the discrete spectrum of N points. Then fb is obtained by the peak frequency of the spectrum. Because the discrete spectrum will have a frequency domain sampling interval △f=fs/N.

In the formula, fs is the sampling frequency, and N is the number of sampling points.

The discrete spectrum sampling obtained by FFT generally cannot collect the peak point of signal frequency. That is, the integer multiple of the frequency interval does not coincide with the peak point, which causes the result of FFT analysis to be inconsistent with the actual frequency, resulting in frequency estimation error.

Extended Reading: Case: High Temperature Radar Level Transmitter for Melted Salt-Solar Photovoltaic Power Station

Level Measurement with FMCW Radar in Steam and High Temperature

When the measured medium is heated, or stored products with relevant physical and chemical properties (acids, alkalis, alcohols, etc.), there may be vapor accumulation in the upper space of the measured medium.

There are various vapors in the air in the space between the level gauge and the medium. It will not affect the accuracy and stability of the measurement. The FM continuous wave radar level gauge has this characteristic.

Level measurement by means of ultrasonic or optical (laser) means is a very unstable and inaccurate method. Because the speed of sound propagation depends on the composition of the atmosphere through which it passes. Direct optical visibility is required for measurement by laser means.

Level Sensors for High Temperature Applications

The high temperature and high pressure guided wave radar level sensor is specially designed for high temperature and high pressure occasions. The product is mainly used for liquid level measurement on various boiler drums. Has high safety and accuracy. The highest rated pressure reaches 40MPa. The highest rated temperature reaches 400℃. It is suitable for high and low pressure heaters, condensers and deaerators in thermal power plants. As well as for liquid level measurement under high temperature, high pressure, vacuum and other steam conditions.

Hydrostatic level transmitter is also called hydrostatic level gauge. The rod-type Hydrostatic level transmitter utilizes the linear relationship between liquid height, density, and pressure. The change of the level is converted into a linear 4-20mADC standard signal output. Suitable for tank level measurement. Flange or threaded installation. Can withstand high temperatures up to 450 ℃.

High Temperature Float Switch

Float level sensor can be widely used for continuous measurement of the liquid level (boundary level): High temperature. High pressure. Viscous, dirty media. Asphalt, wax-containing oil products and flammable, explosive, corrosive media.

Float level sensor (float switch) is one type continuous level sensor for industrial level measurement. Float level sensor has a magnetic float that rises and falls as liquid level changes. The movement of the float creates a magnetic field. Through the magnetic coupling effect, the internal resistance of the sensor changes linearly. The resistance change is converted into a standard current signal of 4 ~ 20mA by an intelligent converter. The percentage of the liquid level, 4 ~ 20mA current and liquid level value, can be displayed on site. Applications like: water tank, fuel tank, level measurement and level control. Vertical, horizontal, and side mounted, all can be satisfied.

Intelligent Solutions for High Temperature and Pressure

Related Blogs

Magnetic Level Gauge/Indicator

What is a magnetic type level gauge? A magnetic Level Gauge is also called a magnetic level indicator. Magnetic Level…

Sino-Inst offers over 10 FMCW Radar High Temperature Level Sensors for level measurement. About 50% of these are Radar level meters, 40% is the tank level sensor.

A wide variety of FMCW Radar High Temperature Level Sensors options are available to you, such as free samples, paid samples.

Sino-Inst is a globally recognized supplier and manufacturer of FMCW Radar High Temperature Level measurement instrumentation, located in China.

Request a Quote

Please enable JavaScript in your browser to submit the form

Miniature Thermocouples–Smaller Than Armored Thermocouples

Miniature thermocouples are smaller than armored thermocouples. It has more advantages, such as: bending, high pressure resistance, fast thermal response time, sturdiness and durability, etc.

Miniature thermocouples are the same as armored thermocouples and assembled thermocouples. As a sensor for measuring temperature. They are usually used in conjunction with display instruments, recorders and electronic regulators. At the same time, miniature thermocouples can also be used as assembly thermocouples. Temperature sensing element. Temperature probes for applications with tight space requirements, limited access or other considerations. Typical miniature thermocouple applications include analytical instrumentation and medical devices.It is an indispensable temperature-measuring device in textile, tape and other industries.

It can directly measure the temperature of liquid, steam and gas medium and solid surface in the range of 0℃~600℃ in various production processes. are especially suitable for temperature measurement and control in narrow and bending places. Widely used in chemical, chemical fiber and pharmaceutical industries

Sino-Inst offers a variety of miniature thermocouple . If you have any questions, please contact our sales engineers.

Technical Parameters

  • Accuracy level: I or II [plus or minus 1.5 degrees below 375° is the first level standard. Plus or minus 2.5 degrees is the secondary standard]
  • Nominal diameter: Φ1 Φ0.5 Φ0.35 [generally the smallest outer diameter]

The Main Technical Parameters Of Miniature Thermocouples

  • Models and Specifications Accuracy grade: I or II
  • Nominal diameter: Φ1
  • Bending radius: R≥5D
  • Nominal pressure: normal pressure

About Temperature

The Celsius Temperature Scale (°C) Stipulates:

Under standard atmospheric pressure, the melting point of ice is 0°C, the boiling point of water is 100°C, and the middle is divided into 100 equal parts, each divided into 1°C, the symbol is °C.

The Fahrenheit Temperature Scale (℉) Stipulates:

Under standard atmospheric pressure, the melting point of ice is 32 degrees, the boiling point of water is 212 degrees, and the middle is divided into 180 equal parts, and each equal part is 1 degree Fahrenheit. The symbol is ℉.

The Thermodynamic Temperature Scale (symbol T)

The thermodynamic temperature scale (symbol T) is also called the Kelvin temperature scale (symbol K), or absolute temperature scale, which stipulates that the temperature when the molecular motion stops is absolute zero.

Principle Of Operation

In 1821, the German physicist Thomas Johann Seebeck discovered that when different metals are joined at the ends and there is a temperature difference between the joints, a magnetic field is observed. At the time, Seebeck referred to this consequence as thermo-magnetism. The magnetic field he observed was later shown to be due to thermo-electric current. In practical use, the voltage generated at a single junction of two different types of wire is what is of interest as this can be used to measure temperature at very high and low temperatures. The magnitude of the voltage depends on the types of wire being used. Generally, the voltage is in the microvolt range and care must be taken to obtain a usable measurement. Although very little current flows, power can be generated by a single thermocouple junction. Power generation using multiple thermocouples, as in a thermopile, is common.

Thermocouple from Wikipedia.

Model And Specifications Of Miniature Thermocouples

ModelGraduationRange of temperature measurement  ℃Thermal response timeMaterial for protective tube
WRE-203SE-40~250<5S1Cr18Ni9Ti
WRE-204SE-40~250<8S1Cr18Ni9Ti
WRE-205SE-40~250<10S1Cr18Ni9Ti
WZP-203SPt100A -30-300       B -50-500<5S1Cr18Ni9Ti
WZP-205SPt101A -30-300       B -50-500<8S1Cr18Ni9Ti
WZP-206SPt102A -30-300       B -50-500<10S1Cr18Ni9Ti

Extended reading:  Tri Clamp Sanitary Thermometers

Miniature Thermocouple Connectors

Standard and miniature connectors are used with thermocouples, extension wires and compensation cables. No false thermal EMFs are created in the connection. Uncompensated miniature copper connectors are also available.

All contacts are polarized. to ensure proper connection. And these connectors are fully compatible with RS thermocouples and thermocouple wiring products of the same type.

Uses: Suitable for thermocouple and RTD connectors.
Suitable for fine wire and mineral insulated cables.

Material
a) Thermoplastic (200℃)
b) Thermosetting (350℃)
C) Ceramic (650℃)

About Sheathed thermocouple: Sheathed thermocouple can directly measure the temperature of liquid, steam and gaseous media and solid surfaces in the range of 0℃~1200℃ in various production processes. Sheathed thermocouples are usually used along with display instruments, recording instruments, electronic computers and so on. It is able to directly measure the temperature of liquid, steam and gas and solid surface in a variety of production processes within the range of 0 ~1300℃.

Extended reading: RTD vs. Thermocouple: What’s the Difference, and Which Should You Use?

Related Blog

Standard Platinum Rhodium Thermocouple

Standard Platinum Rhodium Thermocouple-Platinum Thermocouple Standard Platinum Rhodium Thermocouple is a temperature measurement standard device produced by our company. There…

RTD vs Thermocouple

RTD vs Thermocouple- What is the difference? What are they used for? Both RTDs and thermocouples are sensors used to…

Furnace thermocouple Topics

How does a furnace thermocouple work? In industrial furnaces, armored thermocouples are often used as Furnace thermocouples. The thermocouple body…

Type k thermocouple chart

A thermocouple chart is a practical tool for the electronic query of temperature index. It is used by technicians who…

Mechanical Water Flow Meters

Mechanical water flow meters refer to a type of flow meter suitable for clean water processes or applications. The working…

Sino-Inst, Manufacuturer for Thermocouples, like: Armoured thermocouple, assembly thermocouple, explosion-proof thermocouple, etc.

Sino-Inst’s Thermocouples, made in China, Having good Quality, With better price. Our Temperature measurement instruments are widely used in China, India, Pakistan, US, and other countries.

Request a Quote

Please enable JavaScript in your browser to submit the form