CPC G08B 21/14 (2013.01) [G01N 33/0031 (2013.01); G08B 29/14 (2013.01)] | 20 Claims |
1. A system for redundantly detecting or monitoring a gas, the system comprising:
a signaling module configured to issue audio or visual signals; and
a first gas sensor and a second gas sensor connected in series with each other and the signaling module such that each of the first gas sensor, the second gas sensor, and the signaling module are series connected between a supply voltage and a ground, wherein each of the first and second gas sensors is configured to detect presence of the gas and comprises:
a respective detector switch configured to allow a current through the gas sensor when the gas presence detected by the gas sensor meets a predetermined target, wherein the current causes the signaling module to issue a warning signal, and
a respective fault relay configured to determine a fault of the gas sensor, and upon determination of the fault, shunt the gas sensor and cause the signaling module to issue a fault signal associated with the gas sensor,
wherein the respective detector switch is a normally-open detector switch, such that the current flows through the respective detector switch in response to activation of the respective detector switch and alternatively the current bypasses the respective detector switch in response to activation of the respective fault relay.
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