Ultrasonic level sensors are common in level measurement especially in water treatment. They are safe, clean and accurate. While during the level monitoring, we may find that their accuracy is not stable as expected. Let's discuss this in details.

What happens?

When the probe of ultrasonic level sensor is close to the water surface, the water level can be measured but it fails when the water surface is far away from the probe.

Why it happens?

The liquids generally does not produce steam and mist below 30-40°C. Above this temperature, steam or mist produces easily. The ultrasonic wave emitted by the ultrasonic level gauge will attenuate once through the steam during the emission process. It will be attenuated again when it is reflected back from the liquid surface, causing weak ultrasonic signal. At this time, the liquid level cannot be measured. Under this environment, the ultrasonic level gauge probe is prone to water droplets, which will hinder the transmission and reception of ultrasonic waves.

How to solve?

To solve this problem, we can increase the measuring range. For example, when the actual height of the tank is 2 meters, we can choose an ultrasonic liquid level gauge with measuring range of 4 meters to 6 meters, which can reduce or weaken the influence of steam or mist on the measurement, and besides, we recommend you using a PTFE(polytetrafluoroethylene) or PVDF probe. It is not easy to condense water droplets on the emission surface of such probes.

Actually, during level measurement process, we may face a lot of unexpected or expected problems. Do not worry, Holykell customers have access to professional and experienced engineers who will provide you with perfect solutions. You can contact us now for this service.