AIR CLEANER

摘要

PURPOSE:To contrive the judgement of contamination level with a constant resolving power regardless of variations in reference resistance values by a method wherein an output level in a certain reference resistance value of a gas sensor is made constant and a relative change in amt. against this value is detected to detect a change in the gas amt. CONSTITUTION:A switching means 5 switches a switch 3 to an output state according to a value inputted by a reference value input means 4. A level adjusting means 6 adjusts the detection level obtained by an output level detecting means 2 for an air contamination detecting sensor 1 according to a value inputted by the means 4. A comparing means 8 receives signal from the reference value input means 4 and a comparison value input means 7 for comparison of their values and an output means 9 effects its output according to the results of a comparison made by the means 8. The reference value input means 4 adjusts an output from the detecting means 2 to a predetermined value via a level adjusting means 6 with its output fed in the means 4 and retains thus adjusted output and then sends this output into a comparison value input means 7.