JPS5760235A - Radiation thermometer - Google Patents

Abstract

PURPOSE:To enable a highly accurate measurement of the temperature of a material to be measured by determining the cycle of the charging or discharging to resume the charging when the output of a time constant circuit lowers, depending on the output of a radiation energy from the material as converted photoelectrically and amplified. CONSTITUTION:A radiation energy from material to be measured is inputted into a photoelectric converter 3 with a condenser 2 and an electric signal thus obtained is amplified at a factor of with an amplifier 4 to be inputted to a comparator 5 as an signal Ec. A capacitor C of a time constant circuit 6 comprising a resistance R and a capacitor C is charged with a switch S, upto a voltage E0. The switch S1 is turned off and a switch S2 is turned on to start the discharge. In response to a drop in the voltage below the signal Ec, the comparator provides an output signal and a pulse generator 7, produces a signal with a pulse width t0 to turn off the switch S1, while the switch is turned on to resume the charging of the capacitor upto the voltage E0. In this manner, the charging and discharging is repeated; the output Ec of the amplifier 4 increases as the temperature of the material 1 rises, making the oscillation cycle short and when the temperature drops, the cycle becomes long. This enable the formation of a highly accurate and reliable equipment with a simple circuit.