Principle The capacitance level sensor measuring principle is base on the " capacitance effects " , when this level sensor is set on a silo, it will be formed a condenser between the detector electrode and the silo wall. The capacitance of this condenser varies proportional to the change of material specific inductivity ( DK value) of the material stored in the silo , when the more material substances increased in the silo, the more capacitance value added simultaneously, then it will let his interior circuit "s resonant signal to create a bigger amplitude ,and such a signal amplitude become more or less than factory default threshold value, the relay device will be energized. Features No moving parts inside the device, it will be not affected by friction, which are suitable for powder or liquid application. Various models are suitable for different application. Operating temperature -20 ~ 200°C, Max. 800°C. The sensitivity, which includes 10pf, 20pf and 40pf, is adjustable. With timing delay design, timing adjustable range 0 ~ 6 seconds. Voltage: 110V/220VacC or 24Vdc Output: NPN transistor, 5A/250Vac and 5A/240Vac SPDT contact. Standard connecting screw 1" NPT, special specification are acceptable. Enclosure protection IP65 or explosion-proof. SA-75U Zener barriers inside provide intrinsic safety (Ex ia IIC) to SA17( )D type level switch.
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