Watchdog Works Well Under Pressure

Afriso’s (Germany) Watchdog low gas pressure alarm can be used together with an optional pressure gauge with contacts to monitor and display the pressure in gas-filled containers so that alarms can be generated if the container runs low on gas. A pressure gauge with contacts adapted to the application generates an alarm at the alarm unit via a switching contact if the pressure falls below a threshold (this can be set at the pressure gauge to a value between 5 and 95 % of the range). An alarm is also triggered in the case of a cable break.

The alarm unit is supplied with a AC 230 V. supply. It features an alarm and an operation lamp, a reset and a test button as well as a relay for supplying the signal to additional alarm devices or to Afriso event reporting systems. In the case of an alarm, the person in charge can then be notified via e-mail, SMS or telephone. The low gas pressure device may not be operated in hazardous areas (EX zones); however, as a result of the intrinsically safe control circuit, the connected pressure gauge with contacts is approved for EX zones 1 and 2. (EC Type Examination Certificate no. TPS 03 ATEX 15639 6). For reliable monitoring of several gas containers, it is possible to connect the appropriate number of pressure gauges with contacts in series and use a single low gas pressure alarm to monitor all of them. Typical applications of the low gas pressure alarm comprise decompression stations, cylinder batteries or cylinder combinations.