Ultrasonic Non-Contact Level Measurement

Ultrasonic non-contact level measurement determines liquid level by emitting a high-frequency ultrasonic pulse from a transducer and measuring the time required for the echo to reflect from the liquid surface and return to the sensor. By calculating this round-trip time and accounting for the speed of sound, the system accurately determines the distance to the liquid surface.

Because the speed of sound is affected by temperature, ultrasonic non-contact transmitters continuously measure the temperature inside the vessel and automatically compensate for changes, ensuring reliable and repeatable level readings.

How Ultrasonic Non-Contact Measurement Works

The transducer is mounted above the maximum liquid level, with the ultrasonic pulse directed toward the surface of the media. As the liquid level rises or falls, the return time of the ultrasonic signal changes accordingly. The transmitter converts this time interval into a direct and continuous level measurement. .

By inputting the vessel type and geometry, the device’s electronics can calculate:

• Liquid level
• Liquid volume
• Open-channel flow rate

Common tank shapes, flumes, and weirs are stored within the instrument’s software. For unusual vessels or custom primary flow elements, a 32-point linearization table allows precise configuration.

Common Applications for Ultrasonic Non-Contact Transmitters

Ultrasonic non-contact transmitters are commonly used to measure:

• Liquid level in tanks and vessels
• Liquid volume for inventory and process control
• Open-channel flow in flumes and weirs

Because the sensor does not come into physical contact with the process media, this technology is especially well-suited for applications involving:

• Corrosive liquids
• Suspended solids
• Coating or fouling media
• Wastewater and industrial process fluids