Various sensors can be connected to the GX-A1+ universal gas warning device, but not the CO sensor tested by the TUV, because it communicates with warning devices in a different way. Therefore, we have designed the set GX-A1+CO, which enables you to equip a professional carbon monoxide warning device with an external sensor, in order to position the warning device in front of the room to be monitored, the sensor in it, in order to see from the outside whether the room has to be entered safely. The concentration of carbon monoxide is evaluated and displayed in ppm-exact, in the event of an alarm, a potential-free changeover relay and another relay switches in the event of technical faults detected by the warning device itself, such as a cable break or sensor failure, in order to inform the buildings control technology.THE GAS ALARM GX-A1-CO is a combination of ext. CO-sensor and control device for carbon monoxide and warns of CO concentrations specified in DIN EN 50291 (CO in living roo