Simple gas detector system - uses normally transparent chemical with photodetector and light source monitoring gas induced discolouration

摘要

A gas detector comprises a power source which drives a pulse emitter for the intermittent illumination of a lamp which directs light along an optical path. In the optical path is disposed a chemical detector mounted on a transparent membrane support. A photo detector feeds an amplifier relay which controls a warning device. Presence of a monitored gas causes discolouration of the membrane leading to activation of the warning device.