... the concentration of combustible gases in air. Changes in the conductivity can be ... Module applications:Gas leak monitoring means, suitable for liquefied petroleum gas, butane, propane, methane ... the concentration, the higher the voltage.5 of liquefied natural gas, city gas ... digital 0 and 1 (0.1 and 5V)AO output :0.1-0 .3 V (relative pollution ... diagram of the sensor module New Factory direct MQ-2 smoke ...