| 摘要 |
PURPOSE:To contrive to enhance the measuring sensitivity and accuracy of compensation power, by discriminating the polarity of a detected temp. difference signal and inputting the pulse of an oscillator to a specimen side or a reference substance side heater in response to the discriminated polarity. CONSTITUTION:The temp. difference between a specimen and a reference substance is detected by thermocouples 3, 3' and compensation power is supplied to specimen side and reference substance side heaters 1, 2 so as to adjust a temp. difference signal DELTAV to zero to measure power. A comparing amplifier 4 respectively outputs positive or negative deviation voltage to comparators 5, 6 according to the polarity of the temp. difference signal DELTAV detected by the thermocouples 3, 3'. The comparators 5, 6 respectively output an ON-signal to switch circuits 7, 9 and the switching elements 13, 14 of a power converter 12 corresponding to the positive or negative of deviation voltage to supply the pulses from an oscillator 8 to the specimen side or reference side heater 1 or 2. Pulse counters 9, 10 count said pulses to convert the same to rectangular power waves with positive and negative amplitudes corresponding to the number of respectively counted pulses by D/A converters 15, 16.
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