Apparatus and process for detecting a target gas using multiple detector-compensator pairs

A gas detection device which is configured to detect a presence of at least one combustible target gas in a gas sample and/or to determine a concentration of the target gas in the gas sample, the gas detection device comprising:

• a detection arrangement comprising three detection units, wherein the detection units comprise two detectors and a compensator and forms two different detector-compensator pairs comprising exactly one detector and exactly one compensator, wherein a number of detectors is greater than a number of compensators, wherein the compensator belongs to two different detector-compensator pairs;
• a measuring unit;
• and
• a signal-processing evaluation unit,
• wherein the gas detection device is configured to switch each detector-compensator pair on and off independently of any other detector-compensator pair,
• wherein the gas detection device is configured such that at any time at most one detector-compensator pair is switched on to provide a switched-on detector-compensator pair and each other detector-compensator pair is switched off,
• wherein the switched-on detector-compensator pair has a continuous or pulsed electrical voltage applied at least temporarily to the detector and a continuous or pulsed electrical voltage applied at least temporarily to the compensator of the detector-compensator pair,
• wherein the applied electrical voltages cause the detector and the compensator to heat up,
• wherein each detector is configured such that heating of the detector causes oxidation of target gas, the oxidation releasing thermal energy which acts on the detector,
• wherein the compensator is configured such that heating of the compensator causes less oxidation of target gas than heating of the detector or even causes no oxidation,
• wherein each detector-compensator pair has a detection variable that correlates with the thermal energy released by the detector-compensator pair during oxidation,
• wherein the measuring unit is configured to measure, for each detector-compensator pair, a value of the detection variable for the detector-compensator pair,
• wherein the evaluation unit is configured to determine whether the target gas is present or to determine the target gas concentration depending on the measured value of the detection variable for the switched-on detector-compensator pair, and
• wherein the gas detection device is configured to switch on each detector-compensator pair to effect the measurement of the respective detection variable and the determination whether the target gas is present or the target gas concentration determination and to switch off the detector-compensator pair.