Measuring instrument for combustible gas concentrations in air - is unaffected by changes in gas mixture conductivity or ambient temp.

摘要

Gas concentration is measured by burning at a catalytic electrically heated element connected in a measuring bridge. The bridge is connected to a derivation device which is connected in turn through an integrating device to a measuring instrument, e.g. a voltmeter. The integrating device is connected to a time control circuit which is also connected to the bridge. Two identical electric heating elements are used, one for making the measurement, and the other as a comparison, and the other two arms of the bridge comprise resistors.