An ultrasonic sound pulse is emitted up to 3 times per second from the base of the transducer. The pulse travels through air, reflects against the process medium below and returns to the transducer. The sensor measures the pulse time of flight between sound generation and receipt, and translated this into distance or liquid level height within the vessel.
The ideal electrode is the WEL series. This offers a differential amplifier, easily replaceable electrode cartridge and optional temperature signal.
Walchem can provide a preamplifier that can accept the necessary power, and can connect with any standard electrode with a BNC connector on the cable.