Non Contact Level Transmitters: Types & Industrial Applications

Non Contact Level Transmitters are now more and more widely used in industrial level monitoring. We most often provide customers with non-contact radar level transmitters and ultrasonic level meters. Both liquids and solids can be measured with Non Contact Level Transmitters. There is no need to dig the level probe deep into the measured medium. The sensitive elements measured by Non Contact Level Transmitters are not in contact with the liquid being measured. It can be used in special occasions that contact measuring instruments cannot meet. Such as the medium with high viscosity, strong corrosiveness, strong pollution and easy crystallization.

Non Contact Level Transmitters

Featured Non Contact Level Transmitters for Sale

Non Contact Level Transmitters Types

In order to choose the most suitable level sensor, we not only need to know the properties and state of the liquid being measured. It is also necessary to understand the advantages and disadvantages of different level sensors. in order to select the most suitable sensor. Next, let’s briefly introduce the common non-contact liquid level measurement methods and their characteristics.

Common non-contact measurement methods mainly include ray level meter, ultrasonic level meter, laser ranging sensor and radar level meter.

The rays emitted by nuclear radiation (such as gamma rays, etc.) have strong penetrating ability. And through the medium of different thickness has different attenuation characteristics. The nuclear radiation level meter uses this principle to measure the liquid level.

The nuclear radiation source of the nuclear radiation level gauge is installed outside the oil tank with a point or narrow structure. The elongated nuclear radiation source detection element is also installed outside the oil tank. It can realize the detection of dynamic change of liquid level.

In addition to measuring with nuclear radiation rays, neutron rays can also be used to measure liquid level.

The ray level meter is very convenient to install and has high measurement accuracy.

Because it does not have any parts in direct contact with the measured object. It is especially suitable for measurement problems that cannot be solved by traditional measuring instruments.

Extended reading: liquid nitrogen level measurement

The propagation speed of ultrasonic waves in the same medium is relatively constant. Reflection occurs when it encounters the surface of the object being measured. Based on this principle, an ultrasonic level meter was developed. It calculates the liquid level height by detecting the time difference between ultrasonic transmission and reflection. Therefore, it is easily affected by the energy loss of ultrasonic propagation.

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

The ultrasonic level meter has the characteristics of easy installation and high flexibility. However, when used in environments containing steam and powder layers, the detection distance will be significantly shortened. Not recommended for use in absorbing environments such as foam.

In addition, the accuracy of the ultrasonic level meter is slightly lower than that of the radar level meter, and the price is moderate.

Extended Reading: How to Measure Volume of Liquid

Its measurement principle is similar to that of an ultrasonic level meter. Just use light waves instead of ultrasound. The emission sensor emits laser light and irradiates it to the liquid surface to be measured. Reflection occurs at the liquid surface, and the receiving sensor receives the reflected light. Convert the time from transmit to receive to level.

The beam of a laser is narrow, so its spot is small and concentrated. Therefore, it is very suitable for containers with narrow openings and measurement objects with high temperature and high viscosity.

Laser ranging sensor level meters are easy to install, calibrate, and flexible. The price is relatively affordable, and it can be used for continuous or limit alarms of bulk materials or liquid levels.

If it is a transparent liquid and oil, it is necessary to add a reflective buoy on the liquid surface before it can be measured. Not suitable for use in foam or steam environment (cannot penetrate foam or easily disturbed by steam), fluctuating liquid (easy to cause malfunction), vibration environment, etc.

Radar level meters usually use the principle of frequency modulation radar. Utilize synchronous FM pulse technology. Mount the microwave transmitter and receiver on the top of the tank. A frequency-modulated microwave signal is emitted to the liquid surface.

When the echo signal is received, due to the delay of the round-trip propagation time. The transmission frequency has changed. The two signals are mixed and processed, and the difference frequency of the obtained signal is proportional to the distance between the tank top and the liquid surface.

The radar level meter has a large measurement range and is not affected by harsh weather environments. And easy to install, low maintenance and other advantages,

Especially suitable for high viscosity or high pollution products, such as asphalt. Radar level meters provide high measurement accuracy and do not require regular maintenance and recalibration. But the installation is more complicated and the price is relatively high.

Extended reading: Oil-water interface measurement-Magtech magnetic level indicator

Radar Type Level Transmitter Working Principle

Radar Level Measurement and guide wave radar level measurement Image source:

Very short microwave pulses with very low energy are transmitted and received through the antenna system. The radar wave runs at the speed of light. The operating time can be converted into level signals by electronic components. A special time extension method can ensure stable and accurate measurement in a very short time.

Electromagnetic waves propagate in the air at the speed of light. The distance between the radar level gauge and the surface of the material can be expressed by the following formula:   

D = (1/2)*CT

In the formula:

D ———the distance between the radar level gauge and the surface of the material;   

C ———Speed of light   

T ———Pulse time.

Then the liquid level is:   L = E-D

In the formula:

L — liquid level;   

E ———The total height of the tank;   

D ———Air height.

Even in the presence of false reflections, the new micro-processing technology and the unique ECHOFOX- software can accurately analyze the level echo. By inputting the size of the container, the distance value can be converted into a signal proportional to the level. The instrument can be debugged with empty positions.

Extended reading: Amazing Solutions for Continuous Liquid Level Measurement

Ultrasonic Level Transmitter Working Principle

The working principle of the ultrasonic level sensor is:

Ultrasonic transducer (probe) emits high-frequency pulse sound waves, and the surface of the measured level (material) is reflected back. The reflected echo is received by the transducer and converted into an electrical signal. The propagation time of the sound wave is proportional to the distance from the sound wave to the surface of the object.

The relationship between the sound wave transmission distance S and the sound speed C and the sound transmission time T can be expressed by the formula: S=C×T/2.

The probe part emits ultrasonic waves, which are then reflected by the liquid surface. The probe part is received again. The distance from the probe to the liquid (object) surface is proportional to the elapsed time of the ultrasonic wave:
hb = CT2
Distance [m] = time × speed of sound/2 [m]
The temperature compensation formula of sound velocity:
Ambient sound velocity = 331.5 + 0.6 × temperature

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

Non Contact Level Transmitters Industrial Applications

Sino-Inst’s Non Contact Level Transmitters, whether ultrasonic level meter or radar level meter, are widely used in various industries.

Highly toxic medium
liquid chlorine
Liquid ammonia
dimethyl ether

Oil, flammable and explosive media
gasoline and diesel
heavy oil

Volatile media in pressure vessels
liquefied gas
liquified natural gas

Corrosive media
Anhydrous hydrogen fluoride

Other media
fuel styrene
wax oil

  • Chlor-alkali
  • Storage and transportation
  • petrochemical
  • Coal chemical industry
  • oil refining
  • Fluorine chemical
  • fertilizer
  • pesticide
  • electricity
  • liquid storage
  • other industry

Extended reading: Oil-water interface measurement-Magtech magnetic level indicator

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Non contact level sensor refers to a type of level meters that the liquid level sensor does not need to contact the measured medium during measurement.
Common Non contact level sensors include ultrasonic level meters and radar level meters.

Extended Reading: Silo/Bin material level measurement system

There are 7 main types of level transmitters that Sino-Instrument offers. Each type of transmitter works in a different way, and makes it useful for different types of processes.

For more about: Types of Level Transmitters

Non contact water level sensor refers to the radar water level sensor. Radar Water Level Sensor is suitable for water level monitoring of lakes, rivers, reservoirs, open channels, and tidal water levels.

Radar Non-Contact Water Level Sensor adopts a non-contact measurement method and does not touch the water body. It is not affected by water quality, sediment and floating objects. The RS-485/RS-232/4-20mA interface can realize data long-distance wired transmission or docking with SCADA hydrological telemetry system. The measuring distance can be up to 70 meters.

Extended Reading: Dielectric constant for radar level transmitter

The non-contact liquid level meter has its unique advantages. There is no need to install the sensor on the tank wall during installation, and the instrument does not contact the liquid medium in the container. It effectively solves the technical problem of measuring liquid level under special harsh and harsh conditions such as strong corrosion, high toxicity, high pressure, flammability and explosion, high purity, and no bacterial infection.

Extended reading: Capacitance level sensor advantages and disadvantages

Read more about: River Water Level Monitoring System

Sino-Inst is Manufacturer of Non Contact Level Transmitters. We supply more than 20 kinds of Non Contact Level Transmitters. 40% ultrasonic level meters, 40% radar level transmitters and 20% other types of flowmeters.

Non Contact Level Transmitters are mainly used for level measurement of various liquids and solid particles.
It can measure even liquids such as water, seawater, oil, and slurry.

Non Contact Level Transmitters enable stable level measurement without tank modifications. This greatly meets the measurement needs of many applications. Can be used from small to large tanks.

Sino-Inst’s Non Contact Level Transmitters, made in China, Having good Quality, With better price. Our level measurement instruments are widely used in China, India, Pakistan, the US, and other countries.

The entire team at Sino-Inst’s has received excellent training, so we can ensure that every client’s needs are met. For assistance with your product requirements, whether it’s a Non Contact Level Transmitters, flow sensor, or other device, give us a call.

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About KimGuo11

Wu Peng, born in 1980, is a highly respected and accomplished male engineer with extensive experience in the field of automation. With over 20 years of industry experience, Wu has made significant contributions to both academia and engineering projects. Throughout his career, Wu Peng has participated in numerous national and international engineering projects. Some of his most notable projects include the development of an intelligent control system for oil refineries, the design of a cutting-edge distributed control system for petrochemical plants, and the optimization of control algorithms for natural gas pipelines.