(EP806655-A2)       Process for detecting CH4 with a Ga2 O3 sensor comprises:(a) operating the sensor at a 1st temperature (01) and whose signal (Gs) is compared with a 1st threshold value (SWEtOH); (b) in case the signal (Gs) is below the 1st threshold value, repeating step (a), and if exceeding the 1st threshold value, carrying out step (c); (c) increasing the sensor temperature and measuring the corresponding sensor signals (G(t1 ), G(t2 )) to two different time points (t1, t2); (d) forming the ratio from signals (G(t2 )) and (G(t1 )) and comparing the ratio with the 2nd threshold value (SWCH4 ); and (e) in case the ratio exceeds the 2nd threshold value, repeating step (a) and in case the 2nd threshold value is not exceeded, CH4is present.    USE -    Used in the detection of CH4in a gas mixture containing pollutant gases.    ADVANTAGE -    CH4 detection and CH4 concentration measurement is possible with conventional Ga2 O3sensors without modifying the sensor elements.    (JP10054816-A)       Process for detecting CH4 with a Ga2 O3 sensor comprises:(a) operating the sensor at a 1st temperature (01) and whose signal (Gs) is compared with a 1st threshold value (SWEtOH); (b) in case the signal (Gs) is below the 1st threshold value, repeating step (a), and if exceeding the 1st threshold value, carrying out step (c); (c) increasing the sensor temperature and measuring the corresponding sensor signals (G(t1 ), G(t2 )) to two different time points (t1, t2); (d) forming the ratio from signals (G(t2 )) and (G(t1 )) and comparing the ratio with the 2nd threshold value (SWCH4 ); and (e) in case the ratio exceeds the 2nd threshold value, repeating step (a) and in case the 2nd threshold value is not exceeded, CH4is present.    USE -    Used in the detection of CH4in a gas mixture containing pollutant gases.    ADVANTAGE -    CH4 detection and CH4 concentration measurement is possible with conventional Ga2 O3sensors without modifying the sensor elements.    (US5889198-A)       Process for detecting CH4 with a Ga2 O3 sensor comprises:(a) operating the sensor at a 1st temperature (01) and whose signal (Gs) is compared with a 1st threshold value (SWEtOH); (b) in case the signal (Gs) is below the 1st threshold value, repeating step (a), and if exceeding the 1st threshold value, carrying out step (c); (c) increasing the sensor temperature and measuring the corresponding sensor signals (G(t1 ), G(t2 )) to two different time points (t1, t2); (d) forming the ratio from signals (G(t2 )) and (G(t1 )) and comparing the ratio with the 2nd threshold value (SWCH4 ); and (e) in case the ratio exceeds the 2nd threshold value, repeating step (a) and in case the 2nd threshold value is not exceeded, CH4is present.    USE -    Used in the detection of CH4in a gas mixture containing pollutant gases.    ADVANTAGE -    CH4 detection and CH4 concentration measurement is possible with conventional Ga2 O3sensors without modifying the sensor elements.    (JP2960696-B2)       Process for detecting CH4 with a Ga2 O3 sensor comprises:(a) operating the sensor at a 1st temperature (01) and whose signal (Gs) is compared with a 1st threshold value (SWEtOH); (b) in case the signal (Gs) is below the 1st threshold value, repeating step (a), and if exceeding the 1st threshold value, carrying out step (c); (c) increasing the sensor temperature and measuring the corresponding sensor signals (G(t1 ), G(t2 )) to two different time points (t1, t2); (d) forming the ratio from signals (G(t2 )) and (G(t1 )) and comparing the ratio with the 2nd threshold value (SWCH4 ); and (e) in case the ratio exceeds the 2nd threshold value, repeating step (a) and in case the 2nd threshold value is not exceeded, CH4is present.    USE -    Used in the detection of CH4in a gas mixture containing pollutant gases.    ADVANTAGE -    CH4 detection and CH4 concentration measurement is possible with conventional Ga2 O3sensors without modifying the sensor elements.