The device is used preferentially in refrigeration Systems for determination refrigerants äs ammonia, R22, R23, R50, R 123, R 134a, R 170, R290, R404a, R 407 a, R 407 c, butane, carbon dioxide etc. Depending on the type of gas and on the gas sensor used, gas concentrations from 10 ppm to 30,000 ppm can be determined.
The Gas alarm control unit GMZ-1/2 is provided with two alarm thresholds. The maximum limit value is adjusted in ppm on two Potentiometers provided with a scale corresponding to the gas.
A zero-potential switch-over contact is provided for each alarm stage. Additionally, it can be delivered with an Output for 0/4 mA to 20 mA.
An array of light-emitting diodes for display the switching state and the gas concentration is provided. Further, a piezo buzzer is built-in for a loud acoustic alarm when the second alarm stage will be exceeded.
For connection of the gas sensor, a 4-wire cable with total shielding is required. Up to 600 m distances, a wire cross section of 0.75 mm2 Cu, up to 1,200 m, a wire cross section of 1,5 mm2 is required