Radar Level Switch Customized Case
- Model: FMW21
- Measuring Range: 0-15m
- Media: Solid Particle Measurement
- Pressure: 16 bar
- Voltage: 24 VDC
- Output: 2-wire (4-20) mA + Relay Output
- Explosion-proof Class: Exia IICT6
- Protection Class: IP67
- Operating Temperature: -40~120°C
- Connection: ANSI 3 inch, 150 Ib RF, Flange. Antenna-76mm lens with purge
- Electrical Connection Port: NPT1/2
- with local display
- with 25 meter cable,
- split screen display
What is the difference between an ultrasonic level sensor and a radar level sensor?
Ultrasonic level sensors use ultrasonic waves for measurement. Radar level sensors use electromagnetic wave technology. So, apart from this significant difference, what are the other differences between the two instruments?
Differences in Measuring Principle
Ultrasonic level meter with microprocessor as the core, to achieve digital level measurement. When working, the sensor (transducer) emits pulsed ultrasonic waves, which are reflected by the surface of the object and then received by the same sensor and converted into an electrical signal.
By calculating the time difference between the emission and reception of the acoustic wave, the distance from the sensor to the object to be measured can be determined. Due to the non-contact measurement characteristics of ultrasonic waves, its application is very wide, no matter liquid or solid material can be easily measured.
Radar level meter adopts high frequency microstrip line circuit design, which can generate a 26GHz microwave pulse signal. With the help of high frequency waveguide technology, the microwave pulse is launched to the surface of the measured medium through the antenna.
When the pulse encounters the surface of the medium, part of the energy is reflected back to the antenna and is received and processed by the internal circuit. Through the time extension technology, the radar level meter can accurately calculate the time interval between the pulse transmission and reception, and then deduce the distance from the antenna to the surface of the medium.
Application Scenario Differences
Due to the different measurement principles of ultrasonic and radar, there are also differences in specific applications.
A radar level meter uses electromagnetic waves for measurement, and its measurement effect will be affected by the dielectric constant of the measured medium. Ultrasonic level meter using mechanical waves for measurement, the measurement effect will be affected by the density of the measured medium. Therefore, when measuring materials with a low dielectric constant, the measurement effect of the radar level meter may be affected.
The measurement range of the radar level meter is wider than that of the ultrasonic level meter. The electromagnetic waves emitted by radar can be measured without the need for a propagation medium. The propagation of ultrasonic waves requires the interaction of acoustic and mechanical waves. Therefore, ultrasonic level gauges are not suitable for conditions such as vacuum, high vapor content, or foam at the liquid level.
In addition, ultrasonic level meters are limited by temperature and pressure. The temperature at the probe generally cannot exceed 80 degrees. And the speed of sound waves can be significantly affected by temperature. At the same time, the ultrasonic level meter also has certain requirements on the pressure, usually working within 0.3MPa. Because too high pressure may affect the normal work of the sounding parts. The measurement effect of the ultrasonic level meter will also be affected when the fog or dust content in the measurement environment is high.
In contrast, the electromagnetic wave characteristics of the radar level meter make it unaffected by vacuum, and it is applicable to a wide range of medium temperatures and pressures. With the emergence of high-frequency radar technology, its application range is further expanded, while the ultrasonic level meter is subject to more restrictions in application.
Differences in transmission elements
The difference between ultrasonic and radar transmitting elements. Ultrasonic level meters use acoustic wave transmitting elements, while radar level meters use electromagnetic wave transmitting elements. This difference not only affects the measurement results of both technologies but also determines their suitability for specific applications.
The transmitting element of an ultrasonic level meter is based on the vibration of a piezoelectric material. Therefore, the application of ultrasonic level meters is limited. It is mainly suitable for atmospheric pressure vessels.
In contrast, radar level meters can fulfill the measurement needs of high-pressure process tanks.
Radar has a wider emission angle, but non-contact radar may not be the best choice in small or slender vessels. Guided wave radar is usually more suitable. In addition, radar level meters are significantly better than ultrasonic level meters in terms of accuracy. Therefore, high-precision radar is preferred for tank measurements.
There are many types of radar level meters, such as horn, rod, cable, etc., which can be adapted to different measurement conditions, making the radar level meter better than the ultrasonic level meter in complex working conditions.
However, special attention should be paid to location selection and blind zones when installing either radar level meters or ultrasonic level meters. For example, installing the meter near an inlet or ladder should be avoided. At the same time, a distance of 300 to 500 mm from the tank wall should be ensured to prevent echo interference. In environments where there is agitation or where the level fluctuates considerably, a suitable installation method is also required to ensure the accuracy of the measurement.
Read More about: Radar Level Transmitter and Ultrasonic Level Transmitter – for Liquid Level Measurement
