PURPOSE: To measure the temperature of a high-temperature body even in a dusty atmosphere with high accuracy by blowing dust in front of a radiation thermometer with liquid supplied impulsively and fixing the peak value of the output of the radiation thermometer in synchronism with the supply of the liquid.
CONSTITUTION: The temperature detection terminal 7 of the radiation thermometer is arranged in front of an observation hole opposite, a peak holding arithmetic circuit 8 is connected thereto, and a synchronizing circuit 9 is further interposed between the circuit 8 and a solenoid valve 6. Consequently, when the valve 6 is opened impulsively for a proper purging time to supply 5 purging liquid into the observation hole 3 impulsively as shown by an arrow G, dust 11 is removed instantaneously from in front of the window 4 and a correct temperature specified value is outputted from the detection terminal 7. At this time, the value from the detection terminal 7 is a peak value, which is measured by a circuit 8 which operates in synchronism with the valve 6 by the circuit 9 and displayed 10. Thus, net fire temperature which is neither affected by dust nor disturbed by the purging liquid is indicated.
TAKEGAWA TOSHIYUKI
TAKAHASHI TAKESHI
CENTRAL RES INST ELECT