METHANE CONCENTRATION MEASUREMENT AND DEVICE TO THIS END Russian patent published in 2014 - IPC G01N27/14 

FIELD: instrumentation.

SUBSTANCE: proposed method uses thermo-catalytical sensor with working element and comparator arranged in reaction chamber with diffusion feed of analysed medium. Said working element and comparator are interconnected in series and connected to DC stabiliser controlled by external signal. With instrument switched on, circuit current is adjusted to set preset initial voltage at comparator whereat working element exceeds that of methane complete oxidation start temperature. Thereafter, circuit current is fixed and kept permanent unless instrument switch-off. Working element initial voltage is measured and memorised. Low concentrations of methane are defined using the working element voltage as an output signal. At a time, comparator voltage is controlled unless it reaches preset limit to terminate measurement of voltage at comparator. Voltage at comparator is used as output signal to define methane concentration unless said comparator returns to limit magnitude. Proposed device comprises DC stabiliser controlled by external signal, thermo-catalytical sensor with working element and comparator connected in series, and processor connected via ADC with said sensor to control DC stabiliser to measure voltages at working element and comparator and to process output signals.

EFFECT: expanded range of measurements, higher accuracy.

3 cl, 1 dwg