The NK Ultrasonic Level Switch is used to monitor liquid levels and protect pumps. The ultrasonic function enables the switch to be used wherever traditional monitoring methods fail. The NK can monitor almost all homogeneous liquids regardless of low viscosity, density, solids content or conductivity. The NK utilizes a fork-shaped sensor which contains two piezoelectric crystals facing each other. One of the crystals acts as the ultrasonic transmitter, and the other as a receiver. If the air gap between the points of the fork fills with liquid, the ultrasound passes from one crystal to the other. On receiving the signal, the integral electronics activate a relay output. The devices are equipped with an SPDT relay output. The required function (normally open or normally closed) may be selected using the appropriate connections. The relay is activated in the wet state.
