Radar Water Level Sensor for Non-contact water level measurement. Two-wire system 4…20mA/HART protocol; four-wire system 4…20mA/RS485 Mod bus. Explosion-proof Exia ⅡC T6 Ga / Exd IIC T6 Gb.

Features of SI-FMF13 FMCW Radar Water Level Sensor

• 120GHz (ISM standard band) distance detector based on the working principle of radar.
• FMCW planar microstrip radar non-contact detection. Stable working all-weather.
• The measurement error is less than ±1cm.
• Radar antenna style: 11º×11º. Good directivity, low transmission loss.
• Standard data communication interface (RS-232/RS-485) can be set.
• Low power consumption, waterproof and lightning protection design. Suitable for various outdoor environments.
• Small appearance. Easy to install and easy to maintain.

Specifications of SI-FMF13 FMCW Radar Water Level Sensor

Measuring medium:	Liquid
Measuring range:	0.1m~100m
Process connection:	Flange≥DN80
Process temperature:	-40～110℃
Process pressure:	-0.1～0.3 MPa
Accuracy:	±5mm (range between 35m-100m) ±2mm (range under 35m)
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

Lake Water Level Sensor

Radar water level sensor monitors the water level of rivers, lakes, tidal water reservoirs and reservoirs.

Solution requirements:

The radar water level sensor monitors the water level of rivers, lakes, tidal water reservoirs and reservoirs. It is suitable for installation and use in areas that are not convenient for wiring due to corrosion, pollution, and flood-related water level collection.

Transmit a short microwave pulse, and then measure the elapsed time between pulse transmission and return. The running time of a few meters is measured in units of nanometers. Therefore, a special time conversion program is required to accurately measure these short time periods.

The elapsed time measurement is used to calculate the distance between the sensor and the target (for example, water, grain, slurry). The distance value can then be used to determine the depth of the medium.

Extended reading: Radar Non Contact Water Level Sensor

Technical Support:

Pulse radar level transmitters provide water level measurement based on directly measuring the running time of microwave pulses transmitted to and reflected from the surface of the river being measured. Using rs485 two-wire signal transmission, power supply and low power consumption are safe for outdoor use.

RS485 interface can be connected with 485 line, insert 4g sim card in dtu. 232 to usb to connect to the computer. Open the configuration tool and set the server address and port in the dtu configuration tool.

The server port monitors to receive the data, and it can be analyzed according to the sensor protocol. If the platform is developed to the modbus standard, the sensor also supports modbus. The whole analysis process will be simpler.

Realize remote monitoring and management of liquid level and water level outdoors. Both dtu and sensor industrial-grade outdoor design can be powered by solar energy. Therefore, radar water level gauges can be used in some of the most challenging water level applications.

Advantages:

• dtu rs485 bus access. Multi-device access, support rs232 interface;
• Strong compatibility. Can be connected to five-parameter water quality equipment. Multiple sensors use one gateway;
• Installed on the shore of the water area, on the measuring frame or “extension arm”. Adjust the mounting bracket according to the terrain;
• The installation is simple and the price is low. No need for expensive installation procedures;
• Low power consumption power supply enables the equipment to operate independently in the most remote areas;
• Non-contact measurement principle. Not damaged by silt accumulation or debris;
• Wireless transmission, avoid the trouble of pulling cables. Install and use, remotely unattended;
• High-level industrial requirements for the appearance of the iron shell. Application in hazardous areas and harsh environments;

Extended reading: Capacitive water level sensor

More Water Level Sensors

Sino-Inst offers a variety of water level sensors for a wide range of conditions. Our sensors are ideally suited for monitoring water levels in streams, dams, and reservoirs. Our water level sensor products include:

• Submersible Pressure Transducers
• Radar Level Sensors
• Magnetostrictive Level Sensors
• Pressure Transducers
• Ultrasonic water level sensor

Sino-Inst offers over 10 FMCW Radar Water Level Sensor for level measurement. About 50% of these are float liquid level meters, 40% is the Solid level sensors.

A wide variety of FMCW Radar Water Level Sensor options are available to you, such as free samples, paid samples.

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

Request a Quote

Frequency modulated continuous wave radar also known as FMCW radar. Frequency modulated continuous wave radar level sensors antenna has been further optimized. The new and fast microprocessor can perform higher rate signal processing.

Features of FMCW Radar Level Sensor

• 120GHz-130GHz FM wave radar. Terahertz radar used in industrial measurement field
• 10GHz ultra-large FM scanning frequency width. Wide application range
• 320*240dot TFT color LCD display. Easy to operate and friendly interface
• Support standard HART, MODBUS, PROFIBUS bus protocol
• Support multiple operation and configuration methods such as PC setting software, mobile phone APP, LCD keyboard module, tank side meter, etc.
• 24VDC, 220VAC two power supply models
• Simple installation structure. Adapt to various installation forms on site

Specifications of SI-FMF12 FMCW Radar Level Sensor

Measuring medium:	Liquid
Measuring range:	0.05m~35m
Process connection:	G2A thread/flange≥DN65
Process temperature:	-40～110℃
Process pressure:	-0.1～1.6 MPa
Accuracy:	±2mm
Protection level:	IP67
Frequency Range:	IP67
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: Influence of Dielectric Constant on Liquid Level Measurement | Radar-Guided Wave Radar Level Meter

Frequency modulated continuous wave radar pros

120GHz-130GHz FM wave FMCW radar product (also called THz terahertz radar).
It uses a higher frequency THz band than Ku-band radar.

It has important applications in remote target detection, strong smoke and dust environment, long-distance imaging, multi-spectral imaging, etc. And can detect smaller targets than microwave radar and achieve more precise positioning. With higher resolution and stronger confidentiality.

What are terahertz (THz) electromagnetic waves?

It refers to electromagnetic waves and electromagnetic radiation with electromagnetic wave frequency between 100GHz ~ 10,000GHz (10THz).

This band is the area that humans have the least understanding and application development so far. Terahertz lies between mid-infrared and microwave on the electromagnetic spectrum, and represents the transition stage from quantum mechanism transmission theoretical physics to classical mechanism transmission theoretical physics.

1THz(=1000GHz) The wavelength of electromagnetic wave is 300um (0.3mm is about the diameter of human hair)

Difference between CW radar and FMCW radar

Radars are divided into pulse radars and continuous wave radars according to the types of transmitted signals. Conventional pulse radar emits periodic high-frequency pulses. Continuous wave radar emits continuous wave signals.

The signal emitted by continuous wave radar can be single frequency continuous wave (CW) or frequency modulated continuous wave (FMCW). There are also many ways of frequency modulation. The common ones are triangle wave, sawtooth wave, code modulation or noise frequency modulation.

Among them, the single-frequency continuous wave radar (CW) can only be used for speed measurement, not distance measurement. The FMCW radar can measure both range and speed, and its advantages in short-range measurement are becoming increasingly obvious.

From Wikipedia, we can learn more about Continuous-wave radar.

Frequency Modulated Continuous Wave Radar Working Principle

FM wave radar level sensor and distance formula:

Among them: C speed of light; fd Doppler frequency shift; fu triangle rising edge difference frequency; f0 FM initial frequency; T signal period; B signal bandwidth

The distance resolution depends on the frequency resolution of the DFT operation (Frequency Resolution). The frequency resolution of the DFT Fres is equal to:

①

T is the corresponding sampling time of the non-zero sampling value used for the DFT operation. If you use FFT + zero padding method to calculate the spectrum. T is the time corresponding to the sampled value of the non-zero-filled point.

The distance corresponding to the frequency resolution Fres is the range resolution Sres of the radar. Then, how to calculate the range resolution of the FMCW radar?

B: Frequency modulation width, unit Hz

T: Actual frequency modulation, in seconds

C: Speed of light, 3*10^8 meters/second

S: the distance between the radar and the object, meters

V: Frequency modulation speed, Hz/sec

t: wave propagation time, sec

V=BW/T  ②

t= 2S/C   ③

Assume that T is sampling during the entire frequency modulation period. And all sampling points are used for DFT calculation. According to ④ and ①,

which is

This is the calculation formula for the minimum range resolution that FMCW can obtain when the frequency modulation bandwidth is determined.

In actual use, the sampling time will be slightly shorter than the actual frequency modulation T. That is, Fres will be larger in value. So Sres will also become larger in value.

FMCW vs Pulse radar

VEGAPULS has a good explanation video about PULSE and FMCW technology | Radar level measurement. Let’s take a look together.

Video source: https://www.youtube.com/watch?v=eAngy1B1FP

Pulse Radar

Pulse radar is a precision tracking radar. Each time it emits a pulse, the antenna can form several beams at the same time, and compare the amplitude and phase of the echo signal of each beam.

When the target is located on the antenna axis, the amplitude and phase of the echo signal of each beam are equal, and the signal difference is zero.

When the target is not on the antenna axis, the amplitude and phase of the echo signals of each beam are not equal, resulting in signal difference.

Drive the antenna to the target until the antenna axis is aligned with the target, so that the high and low angle and azimuth angle of the target can be measured.

The sum of the signals received by each beam can measure the distance of the target. In order to realize the measurement and tracking of the target.

FMCW

FM continuous wave radar refers to a continuous wave radar whose transmitting frequency is modulated by a specific signal, such as weather radar.

FM continuous wave radar obtains the distance information of the target by comparing the difference between the frequency of the echo signal at any time and the frequency of the transmitted signal at that time.

The distance is proportional to the frequency difference between the two. The radial velocity and distance of the target can be obtained by processing the measured frequency difference between the two.

Compared with other range and speed measurement radars, the structure of FM continuous wave radar is simpler.

FMCW radar has rich technical experience, low transmit power peak required, easy modulation, low cost, and simple signal processing, so it is a commonly used radar system in automotive radars.

LFMCW radar, i.e., the carrier signal frequency changes linearly with time.

FAQ

Sino-Inst offers over 10 FMCW Radar Level Transmitters for level measurement. About 50% of these are float liquid level meters, 40% is the Solid level sensors.

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

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

Request a Quote

FMCW Radar Level Transmitter with 120GHz fmcw, IP67 anti, can carry out 0.05m~30m Non-contact level measurement.

FMCW

What does Fmcw stand for?

FMCW, namely Frequency Modulated Continuous Wave.

FMCW technology and pulse radar technology are two technologies used in high-precision radar ranging. The basic principle is that the transmitted wave is a high-frequency continuous wave. Its frequency changes with time according to the law of triangle wave.

FMCW (Frequency Modulated Continuous Wave), the received echo frequency and the transmitted frequency change law are the same, both are triangular waves. There is only a time difference. Using this tiny time difference, the target distance can be calculated.

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

FMCW Radar Level Transmitter Working Principle

FM wave radar level sensor and distance formula:

Among them: C speed of light; fd Doppler frequency shift; fu triangle rising edge difference frequency; f0 FM initial frequency; T signal period; B signal bandwidth

The distance resolution depends on the frequency resolution of the DFT operation (Frequency Resolution). The frequency resolution of the DFT Fres is equal to:

 

①

T is the corresponding sampling time of the non-zero sampling value used for the DFT operation. If you use FFT + zero padding method to calculate the spectrum. T is the time corresponding to the sampled value of the non-zero-filled point.

The distance corresponding to the frequency resolution Fres is the range resolution Sres of the radar. Then, how to calculate the range resolution of the FMCW radar?

B: Frequency modulation width, unit Hz

T: Actual frequency modulation, in seconds

C: Speed of light, 3*10^8 meters/second

S: the distance between the radar and the object, meters

V: Frequency modulation speed, Hz/sec

t: wave propagation time, sec

V=BW/T  ②

t= 2S/C   ③

Assume that T is sampling during the entire frequency modulation period. And all sampling points are used for DFT calculation. According to ④ and ①,

which is

This is the calculation formula for the minimum range resolution that FMCW can obtain when the frequency modulation bandwidth is determined.

In actual use, the sampling time will be slightly shorter than the actual frequency modulation T. That is, Fres will be larger in value. So Sres will also become larger in value.

LFMCW, FMCW and Pulse radar

Radar (Radio detecting and ranging) means radio search and ranging. It is a device that uses various radio positioning methods to detect and identify various targets, determine target coordinates and other information.

In modern military and production, the role of radar is increasingly showing its importance. Especially in the Second World War, the “British” air battle between the British Air Force and the Luftwaffe made the importance of radar very clear.

The radar is composed of antenna system, transmitting device, receiving device, anti-interference equipment, display, signal processor, power supply and so on. Among them, the antenna is one of the key technologies for radar to achieve large airspace, multi-function, and multi-target. The signal processor is one of the core components of the radar with multi-function capabilities.

There are many types of radars, which can be classified in many ways:
(1) According to the positioning method, it can be divided into: active radar, semi-active radar and passive radar.
(2) According to the installation location, it can be divided into: ground radar, shipborne radar, aviation radar, satellite radar, etc.
(3) According to the type of radiation, it can be divided into: pulse radar and continuous wave radar.
(4) According to the work, it can be divided into long wave bands: meter wave radar, decimeter wave radar, centimeter wave radar and other wave band radars.
(5) According to the purpose, it can be divided into: target detection radar, reconnaissance radar, weapon control radar, flight support radar, weather radar, navigation radar, etc.

Pulse Radar

Pulse radar is a precision tracking radar. Each time it emits a pulse, the antenna can form several beams at the same time, and compare the amplitude and phase of the echo signal of each beam.

When the target is located on the antenna axis, the amplitude and phase of the echo signal of each beam are equal, and the signal difference is zero.

When the target is not on the antenna axis, the amplitude and phase of the echo signals of each beam are not equal, resulting in signal difference.

Drive the antenna to the target until the antenna axis is aligned with the target, so that the high and low angle and azimuth angle of the target can be measured.

The sum of the signals received by each beam can measure the distance of the target. In order to realize the measurement and tracking of the target.

FMCW

FM continuous wave radar refers to a continuous wave radar whose transmitting frequency is modulated by a specific signal, such as weather radar.

FM continuous wave radar obtains the distance information of the target by comparing the difference between the frequency of the echo signal at any time and the frequency of the transmitted signal at that time.

The distance is proportional to the frequency difference between the two. The radial velocity and distance of the target can be obtained by processing the measured frequency difference between the two.

Compared with other range and speed measurement radars, the structure of FM continuous wave radar is simpler.

FMCW radar has rich technical experience, low transmit power peak required, easy modulation, low cost, and simple signal processing, so it is a commonly used radar system in automotive radars.

LFMCW radar, i.e., the carrier signal frequency changes linearly with time.

More Featured Radar Level Transmitter

Sino-Inst offers over 10 FMCW Radar Level Transmitters for level measurement. About 50% of these are float liquid level meters, 40% is the Solid level sensors.

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

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

Request a Quote