Considerations When Selecting an Ultrasonic Level Meter

Considerations When Selecting an Ultrasonic Level Meter

An ultrasonic level meter can only be used with media capable of adequately reflecting and transmitting sound waves. This is because the operating principle of an ultrasonic level meter relies on sound wave reflection to measure the liquid level. For example, in media such as clean water or common oils, sound waves can be well reflected and transmitted, enabling accurate measurement. However, for media with strong sound-absorbing properties—such as certain types of foam or substances with high acoustic absorption—an ultrasonic level meter is not suitable. In such media, sound waves are heavily absorbed during transmission and cannot be effectively reflected back to the sensor, resulting in inaccurate measurements or even measurement failure.

Ultrasonic level meters cannot be used in vacuum environments and are not suitable for negative-pressure conditions. As is well known, ultrasonic waves require air as a medium for propagation. In a vacuum, there is no medium for sound to travel through, making measurement impossible. In negative-pressure environments, the thin air severely impedes sound transmission, causing increased attenuation and therefore large measurement errors or inability to measure at all. For example, ultrasonic level meters cannot be used in highly vacuumed laboratory equipment or extremely negative-pressure containers.

If the measured medium is volatile, or contains significant amounts of moisture, dust, bubbles, or suspended particles, an ultrasonic level meter is not recommended. When the emitted sound waves encounter such media, irregular reflection and scattering occur. For instance, in dusty media, sound waves interact with dust particles during propagation, altering their transmission path and preventing the sensor from receiving normal signals. Additionally, these media absorb sound waves, causing attenuation that severely affects measurement accuracy.

If there are obstacles or equipment inside the container that affect the propagation of sound waves, selecting an ultrasonic level meter is not advisable. For example, internal structures such as complex piping or mixing devices interfere with normal sound transmission and reflection, resulting in inaccurate level measurements.

Ultrasonic level meters are generally suitable only for applications within normal temperature and pressure ranges. Typically, excessively high pressure can strongly inhibit the speed of sound, affecting measurement accuracy or preventing measurement altogether. In addition, the operating temperature generally should not exceed 100°C.