| 摘要 |
PURPOSE:To enable the accurate measurement of the absolute temperature of the subject even when the ambient temperature exceeds the maximum set temperature by adding the temperature signal clamped to the detection level of a reference infrared ray to the temperature detection signal of a reference black body furnace. CONSTITUTION:If the ambient temperature of a reference black body furnace 1 is 40 deg.C or less where the conditions of a bridge circuit 4 are determined at a temperature 40 deg.C, the temperature of the black body furnace 1 is maintained at 40 deg.C by the feedback circuit consisting of a temperature detecting element 3 bridge circuit 4 driving circuit 6 heater 2 element 3. In this case, the output voltage V of a differential amplifier 5 rises at 40 deg.C or more with respect to the ambient temperature as shown in the characteristic figure. Hence, the voltage V as a black body furnace temperature signal is supplied to an adder 12 and is added to the temperature signal clamped to the detection level of the reference infrared ray from a clamp circuit 10, by which the signal accurately corresponding to the absolute temperature of the subject within the visual field may be obtained from the circuit 12. |
