METHOD TO DETECT METHANE IN AIR Russian patent published in 2014 - IPC G01N25/36 

FIELD: measurement equipment.

SUBSTANCE: invention relates to the field of thermochemical gas analysis and may be used in control of methane content in air. The difference of the proposed method consists in the fact that measurements are performed on a single sensitive element that operates in pulse mode. Differential quality of the output signal is achieved by formation of two measurement steps in the pulse that differ by amplitude and temperature, one of which (No.1) corresponds to the lower border of kinetic area of catalysis, the other (No.2) - the lower border of the diffusion area of catalysis. They stay at these steps until thermal balance is achieved, and readings are taken, and the value of the output signal is determined in the following sequence: in clean air they measure value of a signal on steps No.1 (U°₁) and No.2 (U°₂), they calculate their difference ΔU°=U°_{2 -} U°₁ and take ΔU° as virtual zero. If there is methane available, they measure current value of signals U₁ and U₂, they calculate their difference ΔU=U₂-U₁ and determine the differential output signal S_outp=ΔU-ΔU°.

EFFECT: increased accuracy of methane content detection.

2 cl, 8 dwg, 6 tbl