Any leakage in the cabinet interior of gas analyzing systems may result in explosive gas concentrations. Not being provided with an own explosion protection, the systems need to be monitored respectively. In the event of a leakage, the completely controlled system will be switched off the voltage by the LCS1. The system will not be re-connected to the supply voltage before the gas concentration falls short of the preset gas limit value. The measuring sensor probe installed in the system is approved for being operated in the zones 1 and 2 of explosion risk areas according to the requirements for explosion proof equipment.