| 摘要 |
PURPOSE:To compensate the temp. by varying the differential characteristic according to the temp. variation in an apparatus in which the concn. is calculated based on the output of a circuit for differentiaing the output of an oscillating part in which the oscillation cycle is varied in correspondence to the impedance variation of a detecting part. CONSTITUTION:The resistance value of a detecting part 1a in which the resistance value is decreased in correspondence to the raise of gas concn., and the output of the oscillating part containing an operational amplifying circuit 2 having oscillation cycle determined by the capacity of a capacitor C1 are differentiated by the differentiating circuit composed of a capacitor C2 and a temp. compensating element 3, and the varied part due to the surrounding temp. of the part 1a is compensated by the varied part due to that of the element 3. The differential output is subjected to half-wave rectification by a diode D1, then impressed on the positive terminal of an arithmetic amplifying circuit 4 to which a standard voltage VS is impressed on the negative terminal to obtain a pulse- state output. Further, the average value of the area of the pulse-state detected signal in a prescribed time is processed arithmetically in accordance with the clock output timing from a clock output part 5 at an arithmetic part 6. |
