The new GX-A1+ is the direct successor of the long-proven GX-A1. It is an evaluation unit for gas sensors that change an analogue voltage when the gas is detected. If required, the old GX-A1 can be replaced directly with the new GX-A1+ without changing the installation. All previous ports are in the same positions.The display lighting flashes visually and a loud piezo sound generator provides an acoustic alarm. In addition, a potential-free change-over relay switches, for example, to close a magnet shut-off valve or to switch off a connected gas-thermal bath directly. A further change-over relay switches in the event of internal technical faults, in order to inform the building control system of the fault, for example.Only one gas sensor can be connected to the GX-A1+, depending on the type of gas and suspected source, the correct sensor must be selected. In addition, the installation height decides either the sensitivity (carbon dioxide) of the sensor or the choice of source (natural