| 摘要 |
PURPOSE:To perform a calibration at each temperature fully automatically by setting arbitrary low temperature conditions along a broad range. CONSTITUTION:A preset signal is transmitted to a voltage generator 18 from an electronic computer CPU and applied to a temperature regulator 19. A thyristor 22 is controlled, and a refrigerant is made to be a specified temperature by an electric heater 21. A signal, which corrects the difference between the temperature of the refrigerant measured by a reference resistance thermometer 12 and a preset temperature is sent to the regulator 19 from the electronic computer. Therefore the temperature of the refrigerant in a low temperature tank 4 agrees with the value measured by said thermometer 12. The terminal voltages of a first reference resistor 13, the reference resistance thermometer 12, a second reference resistor 16, and resistance thermometers to be tested 15, 15'... are scanned by a scanner 11 and measured by a digital voltmeter 10. The measured result and the current flowing first and second series circuit 14 and 17 are processed in the electronic computer CPU, and the temperatures measured by the reference resistance thermometer 12 and the resistance thermometer to be tested 15, 15'... are found. |
