An ultrasonic level meter is a kind of liquid level measuring instrument that sends out high-frequency ultrasonic pulses through the transducer (probe) and uses the reflection principle to measure the liquid level continuously without contact. Widely used in a variety of open storage tanks. So, what are the advantages and disadvantages of ultrasonic level meters in practical application?
Ⅰ.The advantages of ultrasonic level meter
It can be said that the advantages of ultrasonic level meter are outstanding, mainly reflected in the following aspects:
- Non-contact measurement, stable and reliable, not easily affected by the viscosity and density of the liquid, the measured liquid, whether water, oil, acid, alkali, salt and viscous liquids, can be measured with high precision.
- Can be fixed point continuous measurement, convenient to provide telemetry remote control measurement signal.
- Simple structure, easy to read, easy to install and maintain.
- Safe and clean, long service life of the instrument.
- With temperature compensation function, it can be used in anenvironment with large temperature differences, high precision, strong adaptability and fast response.
- With the RS-485 communication interface, adopting a special echo processing method, effectively avoiding false echo.
- There are three ranges of 5m, 10m and 15m, which can be applied to different industrial environments.
- High explosion-proof grade (explosion-proof 6Gb) and protection grade (up to IP66/IP67).
- PVDF probe can ensure that the instrument can measure reliably in a corrosive liquid or corrosive environment.
- Cost-effective, low maintenance costs.
- The product is small, lightweight, sensitive, high-performance, convenient installation,and easy to use.
Ⅱ The disadvantages of the ultrasonic level meter
Of course. The ultrasonic level meter also has its disadvantages, specifically in the following areas:
The existence of a blind spot
A Blind zone is an instrument that can not measure the region. In the ultrasonic pulse transmission process, the ultrasonic transducer near the small area usually can not receive sound waves. There is no blind zone for receiving sound waves, the size of which is related to the measurement distance of the ultrasound. Generally speaking, the measurement distance is small, the blind zone is small; the larger the measurement distance, the larger the blind zone.
Due to the existence of the measurement blind zone, the ultrasonic level meter can not measure the liquid level into the blind zone. Therefore, when determining the range of the ultrasonic level meter, it is necessary to leave a blind zone margin. Installation of ultrasonic level meter, the instrument probe should be higher than the highest level blind zone, to ensure the safety of the ultrasonic level meter and accurate monitoring of liquid level.
By water mist, dust, foam and volatile media have a great impact
The ultrasonic level meter can not be used for water mist, dust, foam media and volatile media places. Because of this working condition is easy to absorb the sound wave or interfere with the sound wave emission, resulting in signal loss and accuracy degradation, so it is best not to use an ultrasonic level meter in these working conditions.
Easy to be affected by the agitator
Stirrers in containers with stirrers can affect the ultrasonic level meter, forming false reflection echoes and affecting measurement accuracy. You can install the level meter in a position far away from the center of the stirrer, and reduce the speed of the stirrer to reduce the impact of the stirrer on the ultrasonic level meter measurement.
The sound wave should not have obstacles below.
As the ultrasonic level meter uses the principle of acoustic reflection to measure the liquid level, if there is an obstacle, it will affect the ultrasonic emission, resulting in signal loss and affecting the measurement effect.
Measurement is easily affected by temperature
In the actual measurement, temperature changes can lead to changes in the speed of sound, which in turn leads to the emergence of measurement errors. Therefore, the temperature of the measurement medium also has an impact on the ultrasonic level meter, especially in closed containers. This is because when there is a temperature difference between the temperature of the medium and the surrounding temperature, water droplets will condense around the probe, affecting the accuracy of the measurement.
In this case, when installing the ultrasonic level meter, you can connect a compressed air tube to blow against the probe to reduce the medium and the temperature difference between the container and the probe condensed water droplets on the measurement.
It is not suitable forbeingused for pressure vessels.
This is because the pressure on the probe of the ultrasonic level meter has a great impact on the pressure changes will affect the temperature changes, which in turn affects the change in the speed of sound, resulting in measurement errors.
High cost, maintenance and repair difficulties.
Jiechuang Technology is committed to calibration, pressure, flow, level, temperature, display and other high-performance instrumentation research and development manufacturing. Welcome to visit our website (www.bcstgroup.com) to inquire, we are happy to help you out.