The purpose of a capacitive level sensor is to accurately and reliably measure the level of materials in various industrial applications.

Capacitive level sensor can measure the level of highly corrosive medium, high temperature medium and sealed container, regardless of the viscosity, density and working pressure of the medium.

Let’s first get to know the working principle of the capacitive level sensor.

capacitive level Measurement Principle

Have you ever wondered how we can measure the level of material in a tank? Well, that’s where the magic of capacitance level measurement comes in!

Think of a capacitor like two metal plates, with a thin layer of insulation in between. When the plates are close together, they can hold more electrical charge. In this measurement technique, the probe acts as one plate and the tank wall as the other. When the tank is empty, there’s plenty of space between the two plates, meaning they can hold very little charge. But as the material fills the tank, the plates move closer together and are able to hold more charge.

So, by measuring the electrical charge between the probe and the tank wall, we can determine just how full the tank is! It’s like a secret code between the sensor and the material in the tank, giving us the scoop on its contents.

Capacitance level measurement is a straightforward, dependable, and non-invasive way to keep track of what’s inside a tank. So the next time you’re curious about how much material is left, just remember the wonder of capacitance level measurement!

Different types of capacitive level sensors available in the market

We have compiled a list of different types of capacity level sensors available in the market.

• Rod probe sensor – used for point-level sensing of liquids and solids.
• Cable sensor – uses a cable to detect changes in the level of liquids or solids over a larger area.
• High-temperature sensor – designed for use in high-temperature applications such as chemical processing.
• Low-temperature sensor – Cryogenic Level Sensor for Liquid Nitrogen Tank Level Indicator
• Intrinsically safe sensor – designed for use in hazardous environments.
• Coaxial sheath type – suitable for measuring various non-conductive liquids
• Specialized capacitive sensors – designed for specific industries such as food and beverage.

Understanding the different types of capacitive level sensors available in the market is important for selecting the right sensor for your specific needs. Read more about: External Ultrasonic Tank Level Sensor Installation

capacitive level measurement system

Capacitive level measurement systems are an exciting and innovative way to measure the level of liquids in containers. These systems are made up of two key components: capacitive level sensors and a liquid level recorder or volumetric recorder.

The capacitive level sensors are the key to the measurement process. The capacitive level sensors supplied by Sino-Inst all support signal output. Such as 4-20mA signal, pulse signal or communication protocol such as RS485.

The liquid level recorder or volumetric recorder is the electronic unit that processes the signal from the sensors. It is connected to the sensors and is responsible for converting the capacitance measurement into a readable level measurement. The recorder can be configured to provide real-time data , historical data, and alarms. Making it an ideal solution for monitoring and controlling liquid levels in various industrial applications.

In conclusion, capacitive level measurement systems are a powerful and innovative solution for measuring the level of liquids in containers. Whether you’re looking to monitor liquid levels in real-time or need a historical record of your measurements, capacitive level measurement systems you covered.

Read more about: Liquid Volume Sensor? Monitors Liquid Volume Solutions

Applications of capacitive level sensors

Capacitive level sensors are used in a wide range of industries to accurately measure and monitor the level of various materials, making them an essential tool for maintaining efficiency, safety, and productivity.

Here’s a list of various industries that utilize capacitive level sensors:

Industry	Example of Use
Agriculture	Measuring the level of irrigation water and chemicals in storage tanks used for crop production.
Automotive	Measuring the level of liquids in fuel tanks and coolant in engines, and monitoring the level of battery electrolyte in hybrid and electric vehicles.
Chemical	Measuring the level of liquids and powders in various production processes, such as mixers and reactors. Control Engineering
Food and Beverage	Measuring the level of liquids in tanks and containers, such as for dairy products and brewing. Food Engineering Magazine
Manufacturing	Monitoring the level of liquids and powders in various production processes, such as in pharmaceutical production.
Mining	Measuring the level of liquids and slurries in storage tanks and pipelines used in mineral processing, such as copper production. Mining Technology
Oil and Gas	Measuring the level of liquids and solids in various stages of production, such as in oil refineries and natural gas processing plants.
Pharmaceuticals	Measuring the level of liquids and powders in various production processes, such as mixers and reactors. Lab Manager Magazine
Low-temperature liquid measurement	Specially for liquid nitrogen, LNG, liquid ammonia and other low temperature environment liquid level measurement. Customized products.
Power Generation	Measuring the level of liquids and solids in power plant boilers, condensers, and cooling towers, such as in coal-fired power plants.
Water and Wastewater	Measuring the level of liquids in tanks and reservoirs, and monitoring the level of wastewater in treatment plants. WaterWorld

These examples demonstrate the wide range of industries that use capacitive level sensors and the variety of applications for which they are used.

Advantages and limitations of capacitive level sensors

Read more about: Which Sensor Is Best For Water Level?

Factors to consider when selecting a capacitive level sensor

After so many details. You may want to know, how should I choose a suitable capacitive level sensor? By our years of production experience. It is recommended that you consider the following points.

1. Material compatibility: Material compatibility is very important because different materials can affect the accuracy of sensor readings or even damage the sensor. For example, materials such as PTFE or stainless steel can be used.
2. Temperature range: Choosing a sensor that can work within the expected temperature range will ensure accurate readings. For example, common temperature ranges include 80℃, 100℃, high temperature 250℃, low temperature -196℃, etc.
3. Measuring range: For small measuring ranges, a rod-type probe can be selected. For larger measuring ranges, such as 8 meters or 10 meters, a cable-type probe can be selected.
4. Installation options: Installation size and location.
5. Sensitivity: We generally provide a measurement accuracy of 0.5 or 1 level.
6. Output type: For example, 4-20mA, 0-5V signal output. Or RS485, RS232 communication, etc.
7. Pressure range: Common tank pressures include -0.1 MPa to 5 MPa. Some high-pressure sensors can be customized to withstand pressures up to 32 MPa.
8. Special requirements: Such as explosion-proof, hygienic, and other requirements.

By considering these factors, you can ensure that you select a capacitive level sensor that meets the specific requirements of your application.

Of course, except for the capacitance level sensor. Ultrasonic level meter is also a commonly used one. Read More About: Factors To Consider When Choosing Explosion Proof Ultrasonic Level Sensors.

More Tank Level Measurement Solutions

Conclusion

In conclusion, capacitive level sensors are essential components in various industries. As they provide accurate, reliable, and non-contact level sensing. From agriculture to power generation, these sensors have proven to be efficient and effective in providing real-time measurements and controlling industrial processes.

When selecting a capacitive level sensor, it’s crucial to consider factors such as material compatibility, temperature range, measuring range, installation options, sensitivity, output type, pressure range, and any special requirements. Choosing the right sensor for your application will ensure accurate and reliable measurements and improve overall efficiency.

Therefore, if you are considering a capacitive level sensor for your application. You can contact our engnieer, who can help you select the right sensor that meets your specific needs.

Request a Quote

Step 1. Get to know your tank

To choose a suitable Diesel Fuel Level Sensor, you must first understand the conditions of the tank.

How can we understand your tank? Simply put, a list can be compiled.

1. Tank size (preferably with a sketch of the tank)
2. The installation position of the tank. For example, it is a buried tank, an underground tank, or a vehicle-mounted tank.
3. Tank material
4. Density of Diesel Oil
5. Temperature and pressure
6. Installation position and installation dimensions of Diesel Fuel Level Sensor

With the above conditions, Sino-Inst, as the supplier of Diesel Fuel Level Sensor, can know the condition of the tank.

Read more about: Ultrasonic Tank Level Sensors for Tank Level Monitoring

Step 2. Diesel Fuel Level Sensor Types

Diesel fuel level sensors are devices used to measure the level of diesel fuel in a tank.

There are several types of diesel fuel level sensors, including:

Step 3. Measurement Needs

OK. Next, we can sort out our needs, and then match the appropriate Diesel Fuel Level Sensor.

Low Cost

If you are looking to get the right Diesel Fuel Level Sensor at low cost. Then you can choose one from Float Level Sensors and Pressure Guided Submersible Level Transmitter.

Small tanks, such as 2 meters or 3 meters high. Float Level Sensors can be used.
Large tanks, such as 15 meters, 20 meters. You can use the Pressure Guided Submersible Level Transmitter.

High Accuracy

If you need the highest measurement accuracy. Then Radar Level Transmitters is a good choice. The 80GHz Radar Level Meter has an accuracy of up to ±1mm.

• Maximum measuring range of 120m and a minimum blind zone of 8cm;
• 3°antenna beam angle;
• Suitable for small water tanks or small process accessories in narrow spaces.
• Good signal focusing ability can be used for containers with many internal installations.
• Measurement accuracy:±1mm

high temperature and high pressure

High temperature and pressure

If you want to measure under high temperature or high pressure conditions. For example, 200 degrees Celsius. Or 10MPa.

Then you can choose the appropriate one from Capacitive level sensor, Radar level meter, and Magnetostrictive level transmitter.

contact measurement

If you specified that contact measurement is optional. Then you can choose from Float Level Sensors, Pressure Guided Submersible Level Transmitter, Magnetostrictive Level transmitter, capacitive level sensor, etc.

non-contact measurement

If you specify non-contact measurement. Then you can choose the explosion-proof ultrasonic level meter. Or radar level meter.

Output switching value

If you need to measure the diesel oil level, then output the switch signal for the switch of the pump or other components.

Then you can choose the float level switch. Or configure secondary instruments for ordinary liquid level meters, Output switching value.

The tank cannot be opened

If the tank cannot be opened. Then you can choose an externally attached ultrasonic level sensor.

The sensor can be directly attached to the bottom of the tank. easy installation.

• HS-2000 Ultrasonic Tank Level Sensor-External Mounted
• HS-ULC Ultrasonic Level Switch-External Mounted
• HS-ULC-Pro Ultrasonic Non-contact Liquid Level Controller
• Ultrasonic Oil Level Sensor-External Paste-Truck Fuel Tank

Large range

If the tank is larger. The height exceeds 15 meters. Then it is recommended to choose the radar level meter. Or Stainless Steel Level Sensor-Pressure Guided Submersible Level Transmitter.

oil-water interfac

If your tank is mixed with oil and water, it is the oil-water interface that needs to be monitored. Then you can choose: capacitive liquid level sensor or magnetostrictive liquid level transmitter.

Oil-water Interface Level Measurement Guide

Tank volume monitoring

Most of our liquid level sensors can output liquid level signals, such as 4-20mA signal, 0-10V signal, RS485 and so on.

However, the liquid level transmitter alone cannot calculate the liquid volume of tanks of different sizes. It’s too complicated. A separate recorder is required to calculate it.

Combined with Sino-Inst’s volume recorder. It can collect, display and convert the liquid level of various regular and irregular tanks in the industrial field into the corresponding tank volume. It is suitable for monitoring, controlling and collecting various process parameters.

Monitoring liquid volume solutions.

We simply enumerate our common measurement needs here, based on our experience.
If you have other measurement needs, you can contact our engineers for consultation.

Featured Diesel Fuel Level Sensors

Read more about: Factors To Consider When Selecting A Capacitive Level Sensor

More Tank Level Measurement Solutions

Choosing the right diesel fuel level sensor is critical for the smooth operation and maintenance of your diesel-powered machinery or vehicle.

By considering factors such as compatibility, accuracy, type of sensor, material, and brand, you can ensure that you select the most suitable diesel fuel level sensor for your specific needs.

If you don’t know which Diesel Fuel Level Sensor you should choose. Then you can contact our sales engineers.

Request a Quote

Featured Submersible Level Transducers

More Featured Water Level Measurement Solutions

Read more about: Common River Water Level Measurement Methods

Read more about: Ultrasonic Tank Level Sensors for Tank Level Monitoring

The Submersible Level Transducer is based on the principle that the measured static pressure of a liquid is proportional to the height of that liquid. It is made of advanced isolated diffused silicon sensitive element or ceramic capacitive pressure sensitive sensor. Convert static pressure to electrical signal. After temperature compensation and linear correction. A pressure sensor for measuring liquid level that is converted into a standard electrical signal (generally 4-20mA/1-5VDC).

Submersible Level Transducer selects high-quality diffused silicon quartz thin-film sensor as the measuring element. Using a stainless steel housing, the top of the sensor diaphragm is protected with a through-hole stainless steel cap. And make the liquid contact the diaphragm smoothly. The measured liquid level is not affected by changes in the external atmospheric pressure. Accurate measurement and good long-term stability. It can be directly put into water, oil and other liquids for long-term use.

Submersible Level Transducer is widely used in water level measurement. It can also measure corrosive liquids such as hydrochloric acid, sulfuric acid, nitric acid, hydrofluoric acid, sodium hydroxide, hydrogen peroxide, or chemical and electroplating wastewater.

If you need to purchase Submersible Level Transducer, or have any questions about the technology, use and installation of Submersible Level Transducer, please feel free to contact our engineers.

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This is based on our many years of experience in level measurement. Hope this helps.

1. Operating Frequency

Radar level sensors use radio waves to measure the level of solid materials. And the frequency of these radio waves determines the accuracy and reliability of the measurement.

There are two main types of radar level sensors – pulse radar and frequency modulated continuous wave (FMCW) radar. Pulse radar operates at a higher frequency and provides more accurate measurements, but it is also more expensive. FMCW radar operates at a lower frequency and is less expensive, but it is less accurate.

When choosing a radar level sensor, consider the level of accuracy required for your application, as well as your budget.

Our most common ones are 6GHz-26GHz-80GHz-120GHz. You can refer to more 26GHz-80GHz-120GHz radar level meter parameter comparison. List of Radar Level Sensors

2. Material Properties

The properties of the solid material you are measuring will also impact your choice of radar level sensor.

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.

The problem of antenna hanging can not be ignored. Due to the strong adhesion of steam belt material and most mud, the radar level gauge will encounter the problem of antenna hanging.

The coating has no effect on the medium with small dielectric constant, but it will affect the medium with large dielectric constant. Influence of Dielectric Constant on Radar Level Meter

Introducing high-pressure wind to blow the antenna near the antenna can prevent material hanging. Some devices can be optionally equipped with a dust cover. At normal temperature, just cover the antenna with plastic film and clean the hanging material regularly.

Also, if the material is very dense or has a high moisture content. It can affect the accuracy of the measurement. If the material is very abrasive, it can wear down the sensor over time.

Consider the properties of the material you are measuring when choosing a radar level sensor.

3. Environment

The environment in which the radar level sensor will be installed can also impact its performance.

For example, if the sensor will be installed in an area with a lot of dust or steam. This can affect the accuracy of the measurement.

If the sensor will be installed in an area with high temperatures. Make sure the sensor is designed to operate in these conditions. Consider the environment in which the sensor will be installed when choosing a radar level sensor.

4. Storage Containers

The type of storage container in which the solid material is stored will also impact your choice of radar level sensor.

For example, if the container is very large, a long-range radar level sensor may be required. If the container is very tall, a high-level radar level sensor may be required.

Consider the size and shape of the storage container when choosing a radar level sensor.

The first is the range problem. When choosing a radar, there is often a misunderstanding, that is, the selected range should only be greater than the height of the tank. In fact, the range marked on the radar may be its maximum range.

The type selection also depends on the characteristics of the container. For example, whether the surface of the storage tank is smooth or corrugated, or even stirred.

The actual level that can be measured by the same radar level gauge is very different in different situations. For example, a certain liquid level gauge has a range of 30m. It is only a smooth surface liquid that can be measured to 30m. Once it is used in a non-stirred and rippled On the buffer tank, the result is different. When using it to measure the material level of more than ten meters of stirring, the low material level is often not measured. This is actually because the selection range is not enough. After increasing the range, the problem is solved.

5. Safety Considerations

Finally, safety considerations must also be taken into account when choosing a radar level sensor.

For example, if the material being measured is flammable, make sure the sensor is designed for use in hazardous areas.

If the material is toxic, make sure the sensor is designed to prevent contamination. Consider the safety requirements for your application when choosing a radar level sensor.

Featured Radar Level Meters

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

Conclusion

Usually level measurement media include water, slurry and powdery materials. The environment has a good static liquid level as well as a liquid level where a lot of vapor builds up. There are materials with severe dust and more steam environment. There is also pressure. There are also open ones. In short, all kinds of complications abound. So if you want to make good use of the radar level gauge and maximize its value, you must pay attention to these issues.

Choosing the right radar level sensor for solid materials requires consideration of several key factors. Including operating frequency, material properties, environment, storage container, and safety considerations. By taking these factors into account, you can choose a specific me radar level sensor that you needs and provides accurate and reliable measurements.

More Radar Level Measurement Solutions

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classification of radar level transmitter frequency range

The radar level Transmitter is a measuring instrument based on electromagnetic wave emission and reflection reception to judge the level of material. According to the type of transmitted signal, it is divided into two categories: pulse radar and frequency modulation continuous wave radar.

Pulse radar is measured based on time domain reflectometry (TDR). That is, the radar antenna emits high-frequency pulse electromagnetic waves, which propagate at the speed of light.

When encountering the surface of the measured medium, part of the pulse of the radar level Transmitter is reflected to form an echo back To the pulse emission device. The distance between the emission device and the surface of the measured medium is proportional to the propagation time of the pulse. The height of the liquid level is obtained by calculation.

Frequency modulation continuous wave radar is based on the frequency difference of frequency modulation continuous wave (FMCW). That is, the radar uses synchronous frequency modulation technology. The transmitter and receiver are installed on the top.

The transmitter emits a microwave signal whose frequency has been linearly modulated to the liquid surface. When the microwave When the signal propagates down to the liquid surface and is reflected back to the receiver. Due to the time delay, the frequency of the transmitted signal changes. The distance passed by the radar wave is calculated by the frequency difference between the received reflected wave and the transmitted wave.

Generally speaking, the larger the frequency modulation range, the longer the measurement distance, the better the linearity and the higher the resolution.

Microwave refers to electromagnetic waves with frequencies ranging from 300MHz to 3x103GHz, and their corresponding wavelengths range from 0.1mm to 1m. This segment of the electromagnetic spectrum includes decimeter waves (frequency range 300MHz~3GHz), centimeter waves (frequency range 3~30GHz), millimeter waves (frequency range 30~300GHz) and submillimeter waves (frequency range (300MHz~3x103GHz) ) four bands.

The common radars on the market are 6GHz, 26GHz and 80GHz that appeared in the last two years. The wavelength of the 6GHz radar is 50mm, and the wavelength of the 26GHz radar is 11mm, both of which are centimeter wave radars. They belong to microwave radars that work in the centimeter wave band for detection. The wavelength of the 80GHz radar is 4mm, which belongs to the millimeter wave radar working in the millimeter wave band.

Comparison of different frequency radar level transmitters

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

Effect of radar level transmitter frequency range on measurement

The radar level gauge emits electromagnetic waves through the antenna. The higher the frequency of the electromagnetic wave, the higher the energy of the electromagnetic wave. The shorter the wavelength, the more obvious the scattering phenomenon. Conversely, the lower the energy, the longer the wavelength, and the energy is not easily absorbed by the gas phase layer.

For the same size antenna, a liquid level sensor with a wavelength of 1.2 cm and a frequency of 26 GHZ has a gain of 6 times higher than that of a liquid level sensor with a wavelength of 3 cm and a frequency of 10 GHZ. (Remarks: Antenna gain is a parameter indicating the degree of radiation concentration of a directional antenna).

The overall beamwidth of a radar level gauge is inversely proportional to the frequency of the device. Therefore, for the same diameter antenna, if the frequency of the radar level gauge is increased, the beam width will be lower than that of the lower frequency equipment, and the narrow beam can minimize the influence of the nozzle, tank wall and interference.

At the same time, the measurement range of the radar level gauge is also affected by factors such as frequency, antenna size, dielectric constant of the liquid, and process conditions.

Featured Radar Level Transmitters

The difference in application of radar level transmitter frequency range

Dirty and polluted environment

With long-term use, dirt and pollutants accumulated on the antenna will affect the strength and direction of the radar signal. For high frequency signals, any dirt that covers the antenna will absorb more energy, and the direction of the beam may change. This results in a loss of signal strength. So, low-frequency and medium-frequency technologies are more suitable.

Storage tanks with condensate and/or steam

Condensation and steam can cause reflections on product surfaces to be masked by the “noise” of water droplets. This is more of a problem for high frequency signals. So mid and low frequency techniques are a better choice. Antennas with flat, horizontal surfaces should always be avoided for condensation.

High steam and agitation

Be sure to choose the 80G millimeter-wave radar level meter. The 80G radar level meter has a high transmission frequency and has good penetration and is not affected by steam. The 2° transmission angle can effectively avoid the interference of the stirring blade. The unique echo Tracking algorithm avoids reading multiple echoes when the material level is high.

Applications with turbulence, waves and ripples

Waves and ripples are often found on the surface of process liquids in large tanks. And this turbulence is especially detrimental to high-frequency measurements. Low and mid frequency level instruments emit longer wavelengths, making them perform better.

Foam application

Like dust and condensation, a layer of foam on top of the liquid can absorb the radar signal, making accurate measurements more difficult. Low frequencies work best with thick foams, such as beer, molasses, or latex. For lighter foam, the mids perform well. High frequency techniques should be avoided in foam applications.

Read more about: Stilling Wells for Radar Level Measurement

Bulk liquid storage tank

Many bulk storage tanks use floating roof tanks that require level measurement through stilling pipes. Low frequency radars are preferred for these applications as they are less sensitive to buildup on pipe walls. Except in not perfectly straight tanks and pipes. High frequency radars would have difficulty in this situation.

Small and medium container

These vessels are often up to 20 meters (m) high and often present challenging conditions. such as condensation, contamination, turbulence and foam. IF technology is a good choice in this tank because it combines small antennas with good reliability.

Small tank/bucket

In small tanks approximately 0.5 to 1.5 m high, the size and position of the nozzles may be restricted. Short measurement ranges and the need for small antennas mean that HF and MF technologies are attractive options for these applications.

Solid level

For measuring the level of solids, the optimum frequency depends on the application. Low and mid frequencies can handle dust, condensation and coarse solids. High frequency is suitable for fine powder.

Condensation is often challenging for high-frequency radars. But with solids another problem arises: Condensation combined with certain types of solids can lead to rapid buildup of material. This quickly clogs the small nozzle opening and covers the small antenna of the high frequency radar.

Read more: The Impact of Frequency in Non-Contacting Radar Level Measurement by Emerson

More Level Measurement Solutions

Radar level gauge is favored by the majority of users because of its unique advantages. Whether it is toxic medium, corrosive medium or solid medium, it can withstand various harsh measurement conditions and maintain stable and reliable work. Liquid is still dust. Slurry material medium, can achieve stable and accurate measurement.

About What Is Radar Level Transmitter Frequency Range? I hope that through this article, you can have a detailed understanding. Frequency band selection is an important consideration when deciding which non-contact radar device is the best choice for each different level measurement application.

The difference in the application of radar level transmitter frequency range is summed up after our many years of experience.

When measuring steam and foam, and condensate, choose low-frequency radar first.
In most other applications, high frequency radars are preferred for ease of installation. Lower frequencies reduce sensitivity to vapor, foam and antenna contamination.
Low frequency radars have a wider beam velocity angle to better deal with steam, dust, condensation, contamination and turbulent surfaces.
Higher frequencies minimize the effect on nozzles, tank walls and disturbances.

If you need to choose radar level transmitter, or still have doubt about radar level transmitter frequency range. Please feel free to contact our sales engineers.

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Guided Wave Radar Level Transmitter Calibration

1. Through the HART handheld programmer. However, the HART handheld programmer has its adjustment range. It is not applicable to all products. The combined measurement range is the corresponding value of 4-20mA.
2. Adjust the module by hand. Its function is equivalent to an analysis and processing instrument. The programmer consists of keys and an LCD display. Adjustment menus and parameter settings can be displayed.
3. By debugging the software. The guided wave radar level transmitter can be debugged through software.
   The process is: mainly use HART software for debugging. A meter driver is required. Among them, when using software debugging, power up the radar instrument with 24VDC. At the same time, add a 250 ohm resistor to the front end of the HART adapter. If the instrument is powered by an integrated HART resistor, that is, the internal resistance is 250 ohms, no additional external resistance is required. At this time, the HART adapter can be connected in parallel with the 4–20mA line.

The above are relatively common debugging methods and means for guided wave radar level transmitters. You can correspond to your actual situation and judge the most suitable method for you to use. Do it last. Remember to be careful when choosing a method, otherwise errors are prone to occur.

Guided Wave Radar Level Transmitter Troubleshooting

Guided Wave Radar Level Transmitter has many advantages in the level meter field. It generally adopts an integrated design, no moving parts, no mechanical wear, and long service life. And it can be used for level measurement of almost all liquids. However, in the process of use, there will still be inaccurate measurements. What’s the matter?

1. Probe scarring and frequent failures

Solution: The first solution is to increase the installation position of the Guided Wave Radar Level Transmitter probe. However, if the installation condition is limited and cannot be increased, the method of interlocking the liquid level measurement value with the pump of the tank can be used to solve the problem. This problem. Reduce the maximum liquid level set value by about 0.5m. When the liquid level reaches the maximum value, you can stop or start the discharge pump.

2. The effect of foam on measurement

Solution: Both dry foam and wet foam can reflect the radar wave of the Guided Wave Radar Level Transmitter, which has no effect on the measurement. But neutral foam absorbs and diffuses radar waves. Reflections that seriously affect echoes or even no echoes.

Therefore, when the surface of the medium is dense and thick foam, the measurement error of the Guided Wave Radar Level Transmitter will be large or impossible to measure. It is recommended to replace other suitable type of level meter.

3. Antenna scarring

Solution: The hanging material with a small dielectric constant has no effect on the measurement in a dry state. However, the hanging material with a high dielectric constant will affect the measurement. Blowing with compressed air (or flushing with clean water) is recommended, and cooled compressed air can reduce the temperature of flanges and electrical components. Although alkaline scabs can also be cleaned with an acidic cleaning solution, level measurements cannot be taken during cleaning. More about Advantages of Coaxial Probes.

4. Guided Wave Radar Level Transmitter antenna flooded

Solution: Change Guided Wave Radar Level Transmitter to waveguide measurement.

Install the Guided Wave Radar Level Transmitter at the original opening, and the waveguide is about 0.2m higher than the exhaust pipe. In this way, even if there is a bad working condition where the slurry overflows from the exhaust pipe, the level meter antenna will not be damaged The slurry is submerged. And it will not cause the disturbance of the stirrer vortex and a large amount of steam from the probe, which reduces the damage to the probe.

In addition, due to the better focusing effect of the waveguide, the received radar wave signal will be stronger. Therefore, better measurement results can be obtained.

The above content is for reference only. Of course, there are other reasons for the inaccurate measurement of the Guided Wave Radar Level Transmitter, which needs to be checked in combination with the actual situation.

Featured Guided Wave Radar Level Transmitters

More about Guided Wave Radar Level Transmitter technology and application:

• Guided-wave radar (GWR) level transmitter working principle
• Influence of Dielectric Constant on Guided Wave Radar Level Meter
• Guided wave radar level transmitter measures drum level

What is the difference between radar and guided wave radar level transmitter?

1. Different ways of contact:
   Radar level gauges are non-contact. Guided wave level gauge is contact type. That is to say, the guided wave type cannot be used in occasions with high food grade requirements.
2. Different working media:
   The guided wave radar level gauge also needs to consider the corrosiveness and adhesion of the medium. Moreover, the installation and maintenance of guided wave radars that are too long are more difficult.
   In the case of low permittivity, the measuring principle of radar or guided wave radar is based on the difference in permittivity. Since the waves emitted by ordinary radar are divergent, when the dielectric constant is too low, the signal is too weak to measure stably. Guided wave radar waves propagate along the probe, and the signal is relatively stable.
3. Different types of selection:
   Ordinary radar can be used interchangeably. Guided wave radar cannot be used interchangeably because the probe (cable) has a fixed length according to the original working conditions. The selection of guided wave radar is more troublesome than ordinary radar.
4. Different ranging:
   Ordinary radar is mostly used on 30 and 40m tanks, and can even measure to 150m. Guided wave radar also needs to consider the force of the probe (cable). It is precisely because of the force that the measurement distance of guided wave radar is generally not very long.
   However, guided wave radar has obvious advantages in special working conditions such as stirring in the tank and large fluctuations in the medium. The measured value of the guided wave radar fixed at the bottom of this working condition is more stable than that of the flexible radar. And small tanks. For liquid level measurement, due to the small installation and measurement space (or a lot of interference in the tank), general radar is not applicable, and the advantages of guided wave radar are reflected at this time.

More Tank Level Measurement Solutions

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.

Guided Wave Radar Level Transmitter has an absolute advantage in solid working conditions. for example:

1. If there is stirring in the tank and the medium fluctuates greatly, the measured value of the guided wave radar fixed at the bottom is more stable than that of ordinary radar;
2. Level measurement in small tanks.
3. Working conditions with low dielectric constant.
4. The general guided wave radar also has a bottom detection function, which can be corrected according to the measured value of the bottom echo signal to make the signal more stable and accurate.

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

A wide variety of GWR Corrosive Liquid Chemical Level Sensors options are available to you, such as free samples, paid samples.

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

Request a Quote

When do we need to use Stilling Wells?

Usually, the radar level meter is installed in Stilling Wells because the interference signal caused by certain factors has a great influence on the real signal, resulting in measurement errors or even failure to measure. The radar level meter is installed in the Stilling Wells, which can avoid the influence of the interference signal on the real signal and ensure the accuracy of the measurement.

So, under what circumstances will the radar level meter be installed in Stilling Wells?

Situation 1: There are obstacles in the storage tank or large foam and fluctuations on the liquid level. In this case, interfering signals can significantly affect the measurement.

Situation 2: The dielectric constant of the medium is low, and the reflected echo is too small to accurately measure the liquid level. Using the radar level meter installed in Stilling Wells can increase the reflected echo energy and ensure accurate measurement.

Using Stilling Wells installation (Stilling Wells or bypass pipe), you can avoid the impact of obstacles, foam, liquid surface fluctuations in the container on the measurement.

Stilling Wells can only measure medium with good fluidity. Viscous medium cannot be measured with Stilling Wells.

Advantages of Stilling Wells for Radar Level Measurement:

The advantage of Stilling Wells measurement is that the liquid level in the pipe is stable and not disturbed by external fluctuations.
Avoid interference from obstacles inside the container.
Reduce the influence of foam and air turbulence on the measurement.
Increase signal reflection strength.
For the case where the measured object has boiling or turbulent liquid level, or the dielectric constant of the measured medium is small, measures such as Stilling Wells should be used to ensure the measurement accuracy.

The accuracy of the radar level meter differs under actual application and reference conditions. The main reason is that the tank itself has become part of the measurement system. The ability to achieve accuracy is determined by the interference of the microwaves by the tank and its internal obstructions.

After the pressure spherical tank is built, the draft tube becomes a part of the tank body. Its manufacturing process level directly affects the measurement accuracy of the radar level meter.

The electromagnetic wave emitted by the radar level meter propagates along a straight line. When interference is encountered in Stilling Wells, a reflected echo will be generated, and the echo amplitude is small. On the contrary, if the smoothness of the inner wall of the pipe is not ideal, it will show a reflection echo with a large amplitude.

Read More about: List of Differences: Radar vs Ultrasonic Level Measurement

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Radar level meter installation standards

The installation position of the radar level meter affects the measurement accuracy. Pay full attention to several issues:

1. Radar level meter The distance between the tank hole and the tank wall is greater than 15% of the height between the flange sealing surface and the tank bottom plate, so it is limited to using guided waves to close the pipeline.
2. In order to ensure that the sound signal enters the middle of the storage tank unhindered, the total length of the flange and pipe joint of the radar level meter socket is less than 250mm.
3. If there is a waveguide; the waveguide should be horizontally downward, the allowable error ≤ 0.5; the verticality should be 1.
4. Installation and connection should take into account the strength of the tank roof so as not to cause variable displacement.
5. The radar wave path should avoid internal obstacles, such as brackets, heating wires, stirring rods, etc.
6. Consider liquid level conditions and avoid formation of air bubbles such as turbulence at the discharge end.

Radar level meter production requirements

When the storage tank is a floating roof tank or a spherical tank, a waveguide shall be used.
When the medium level fluctuates or foams, the waveguide should also be actively added.

The waveguide is not purchased together with the equipment supply, and should be manufactured on site by the supervisory unit according to the specific working conditions.

The specific conditions for manufacturing Stilling Wells are as follows:

1. Stilling Wells shall be constructed of stainless steel or carbon steel, and only stainless steel shall be used for spherical tanks.
2. Stilling Wells should be complete. If it needs to be lengthened, the jacket welding method must be used. The gap is less than 1.0mm. There should be no welds or sharp edges on the inner wall of the welding. Otherwise, its accuracy will be affected.
3. The bottom of the Stilling Wells is 100~150mm away from the bottom plate of the fuel tank. Then add a reflector radar inclined at 45°.
4. In order to ensure that the liquid levels outside the Stilling Wells are equal, the Stilling Wells must be separated at the intersection holes, and the plane of the Stilling Wells section must be smooth, otherwise false liquid levels are prone to occur. The hole spacing should be appropriate and not too large, so as not to cause fluctuations in the liquid level in the pipe;
5. It cannot be too small, and it is not very effective to ensure that the liquid level inside and outside the Stilling Wells is consistent.

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

Our experience:

Stilling Wells should be made of carbon steel or stainless steel. If it is used in spherical tanks, stainless steel must be used. This is the result of years of experience.

In addition, it is recommended that Stilling Wells be made into whole roots. If lengthening is required, the outer jacket welding method must be used. And the gap should be less than 1 mm. There must be no burrs and welds on the inner wall. Burrs and welds will interfere with the real echo signal and affect the measurement effect.

The last point, which is crucial, is directly related to whether the liquid level is true. Therefore, more attention is required. When making Stilling Wells, it is necessary to use the interval distance to cross the holes. The opening should not be too large, nor too small. If it is too large, the liquid level in the tank will fluctuate easily. If it is too small, the internal and external liquid levels of Stilling Wells cannot be guaranteed to be consistent.

Based on years of experience, some engineers have made a correspondence between the diameter and opening size of Stilling Wells. When the diameter of Stilling Wells is DN125, DN200, DN250 and DN300, the opening sizes of Stilling Wells are 0.1m, 0.4m, 0.8m and 1.2m in sequence.

The above three points are all the experience summarized by Sino-Inst. In addition, some materials have also mentioned that a certain distance should be kept between the bottom of the Stilling Wells and the bottom of the storage tank, and reflectors should be installed. If you have installation needs, you can find more relevant information or ask more relevant engineers.

In order to ensure the accuracy of radar level meter measurement, in addition to installing Stilling Wells, some can also install bypass pipes. You can choose the appropriate method according to your own working conditions.

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The radar level gauge is installed in the waveguide, which can avoid the influence of interference signals on the real signal, increase the reflected echo energy, and improve measurement accuracy. But not all media are suitable for measurement in the waveguide, and viscous media are not.

Therefore, when choosing to install a radar level gauge in the waveguide, it is necessary to analyze the medium and the working conditions to avoid useless work.

Many times, there is more than one way to solve a problem. When there is a problem in the measurement of the radar level gauge, we can think about it and see which solution is most suitable for our working conditions.

If we pay attention to efficiency, then we can find the simplest solution;
If we pay attention to cost performance, we can consider it from the perspective of cost and find the most suitable solution.

Sino-Inst is an instrument manufacturer specializing in R&D, production and sales of radar level meters and radar water level gauges. We supply high frequency radar level meters, explosion-proof radar level meters, FM radar level meters, guided wave radar level meters, pulse radar water More than 10000 level meters.

If you need to purchase radar level meters, or have any technical questions about the application and installation of radar level meters, please feel free to contact us.

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Difficulties in Measuring Powder and Granular Silos

Measurement difficulty 1:

The silo is slender and the space is narrow. The measurement signal is easy to hit the silo wall.

If there are obstacles such as ring beams on the warehouse wall, or material hangs on the warehouse wall due to the humidity of the material. False signals will be generated, which will seriously affect the measurement.

At the same time, due to the narrow space, the measurement signal cannot avoid the material flow. Which will also cause a significant attenuation of the signal.

Measurement difficulty 2:

The dust is large. It will cause great loss to the signal.

As a result, the material level signal is greatly reduced, and even no signal can be recovered.

Measurement difficulty 3:

Adhesion to meter antenna.

For wet materials, the powder is easy to form serious adhesion on the antenna of the radar level gauge;

For dry materials, due to the collision and friction between the particles, the powder is prone to static electricity. This will accelerate the adsorption of the powder on the antenna. And will also cause serious adhesion problems.

Measurement difficulty 4:

The general powder dielectric constant is very low.

For example, fly ash, lime powder, and pulverized coal in power plants. Plastic powder, plastic granules, and catalyst particles in petrochemical plants. In addition, there are alumina powder, silica powder, cement, wood chips, etc. The dielectric constant is very low. For radar As far as the instrument is concerned, it will cause the instability of the material level signal. Even the material level signal cannot be received.

At present, the detection method of silo material level mainly relies on ultrasonic level gauge, radar level gauge, laser range finder and so on.
Some detection methods can only be used as an alarm signal. That is, the material is lower than the material level to replenish the material in time, and the material level is higher than the material level to stop filling.
Some methods are limited by technical principles and have strict requirements on installation conditions.
Some methods are limited by measuring height, making them expensive.

So, why is the radar level meter so popular?

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

Silo Radar Level Measurement-Cement

Material level is one of the main measurement parameters of cement production enterprises. Compared with other production enterprises, cement enterprises measure less liquid level. It is mainly the measurement of the height of solid matter in the production process.

Solid materials are lumpy, granular, and powdery. These materials also vary in dielectric constant, bulk density, temperature range, and moisture content.

The main raw materials for cement production are: limestone, clay (shale, sandstone), iron powder (iron ore, iron slag), coal gangue, industrial waste residue, raw coal, gypsum, slag, fly ash.

The above raw materials enter their respective silos after drying and crushing. At this time, high-frequency Radar Level Meters can be used to monitor the material level.

Contact level measurement is the main measurement method of cement production enterprises in the past. Such as capacitive type, weight level gauge, tuning fork, and other measurement methods. During the contact process of measuring things, measuring instruments and materials, they often face a large number of Routine maintenance. Such as the problem of capacitor material hooking.

By the end of the 20th century, the cement industry started using non-contact level measurement.

The following points should be paid special attention to when cement production enterprises choose Radar Level Meters:

1. Pulse and FMCW radar

Generally divided into two categories: pulsed (impulse) radars and frequency modulated continuous wave (FMCW) radars are used to measure radar levels with level gauges.

Large measurement range and high reliability due to radar transmission power. This is the reason why Radar Level Meters are widely used in the cement industry recently.

2. Selection of granular materials

The raw materials of cement are mostly in granular matter, and some are block materials. Such as limestone, coal, oil shale. It is recommended to use non-contact Radar Level Meters, horn antenna Radar Level Meters.

3. Selection of powdery materials

The materials in the cement and cement grinding warehouses are the cement raw materials. The powder of these materials is difficult to predict the substance level. The surface of the powder is very loose, which is very difficult for microwave reflection. It is recommended to use contact Radar Level Meters, or non-contact radar level gauges with horn antennas. This is a typical radar application in China.

4. Cable

Most of the current Radar Level Meters are integrated and powered by wires. It can be directly connected to the control system module and output 4~20mA analog signals. It can save a lot of cables. It also provides a variety of HART digital signals. Protocol and fieldbus digital communication .The connection of the computer monitoring system is very convenient.

It should be noted that guided wave radar should be used with caution in powder measurement in cement plants. This is because most cement plant drying equipment is not ideal. There is often moisture or even steam. Once condensation will cause various powders to condense on the Caused a fault on the waveguide cable.

In addition, depending on the range, for powdery materials such as fly ash, slag powder, cement products, etc., parabolic antenna radar can also be used.

The level measurement of cement plays a very important role in the automation system of the cement production line. The application of Radar Level Meters can relieve the variety, accuracy, standard substance, pressure, high temperature, explosion. It greatly facilitates the cement production enterprises in the level parameters Accurate measurement on the surface. The existing Radar Level Meters technical level and on-site use are sufficient to meet the requirements of detection and control.

Silo Radar Level Measurement – Grain Silo

There are many kinds of media in the granary, and rice is a kind of grain. Then it is ok to want to use Radar Level Meters to measure the rice in the granary. Radar Level Meters can not only measure the rice in the granary, but also measure various media in the coal bunker.

Radar Level Meters can choose the conventional 26GHz/80GHz planar radar level meter to measure the rice in the granary. The measurement range selected by the selection is a distance of 70m. Debugging mode is with LCD display type. The power supply is 24V. Output signal selection 4-20mA. Can also bring HART protocol.

Silo Radar Level Measurement-Raw Coal

The fuel bunker is usually a raw coal bunker or a pulverized coal bunker, and the medium of the raw coal bunker is raw coal with larger particles and less dust than the pulverized coal bunker. Radar Level Meters are suitable for this situation.

The pulverized coal particles in the pulverized coal bin are small and have a lot of dust. If the proportion of pulverized coal exceeds 70%. In addition, the measurement environment of pulverized coal material level is harsh and the coal quality is unstable. Due to the influence of factors such as the position of the material port, it is more appropriate to use a radar level gauge with stronger anti-interference ability.

The common forms of Radar Level Meters are bell mouth type, parabolic type and rod type. The difference in structure is mainly due to the difference in transmission frequency, beam angle and measurement range. The measurement distance of the fuel tank is not very long, so the commonly used bell mouth radar level gauge is the best choice.

Because of the high reliability, stability and accuracy of Radar Level Meters, it is widely used in fuel tank level measurement. However, in order to obtain accurate material level measurement values, special attention should be paid to the installation of Radar Level Meters to avoid radar echoes being interfered by interference sources.

Here are a few installation tips for Radar Level Meters to measure fuel tanks:
The selection of the installation position needs to be based on the form of the fuel tank, and the top-mounted form is adopted;
In addition, keep a certain distance from the wall of the fuel tank to reduce the reflection and interference of the tank wall;
It is also necessary to keep a certain distance from the discharge port of the fuel bin to reduce the interference of fuel and dust at the discharge port.

Silo Radar Level Measurement-HDPE Pellet Silo

The high-density polyethylene powder silo has a slender body, large dust, and low dielectric constant of the medium; it poses a great challenge to the level measurement.

Aiming at the characteristics and complexity of large powder silo measurement, Sino-Inst’s radar level gauge has a range of up to 120m. Due to its high focus, strong signal, high dust resistance and other characteristics. It can well solve the above measurement difficulties and achieve stable and accurate measurement.

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The powder silo is an application that is difficult to use continuous level measurement in solid level measurement. Especially for large, slender powder silos. Greater challenges are posed to measuring instruments.

Currently on the market, there are mainly capacitance, ultrasonic level gauges, guided wave radar level gauges and high-frequency radar level gauges that can be used to measure powder silos.

Each measurement method has its own advantages and disadvantages. But all in all, Silo Radar Level Measurement is the most successful and widely used.

Especially high-frequency radar level gauges with small emission angles. Thanks to the rapid development of high-frequency radar technology.

It has continuously overcome insurmountable obstacles such as large range, narrow space, high dust, and low dielectric constant in the past. It has achieved great success in the continuous level measurement application of Silo Radar Level Measurement.

If you have any questions about Silo Radar Level Measurement, . Or you need Silo Radar Level Measurement technical support, please feel free to contact our sales engineers.

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