To make it possible to perform precise measurement without being affected by a terminal temperature by a method wherein the measuring terminal, for calibration, and the measuring terminal, for other purpose, of a resistance temperature sensor are provided with pins, for calibration, whose contact faces are plated with gold, which are maintained in an elastic state in a calibration operation and which are made of phosphor bronze.
The measuring terminal terminal, for calibration, and the measuring terminal, for other purpose, of a resistance temperature sensor are provided with pins 11, 12, for calibration, the pins are constituted of phosphor bronze, their contact faces with the measuring terminals are plated with gold, and the pins are maintained to be within the elastic region and the elastic deformation region of every spring 2 in a calibration operation. A prescribed difference in set regarding lengths of the pins 11, 12 for calibration, the pressure force of the pin 11 for calibration is set at, e.g. 1kg or higher so as to be stabilized, and the pressure force of the pin 12 for calibration is set at, e.g. 0.5kg or higher. Since the pins 11, 12, for calibration, which are made of phosphor bronze, i.e., the same material as screw terminals of a measuring apparatus are provided, the generation of a thermoelectromotive force is suppressed. In addition, since the contact faces with the measuring terminals are plated with the gold whose thermal conductivity is twice that of the phosphor bronze, even a very-small- voltage measuring apparatus which is affected by a terminal temperature can be calibrated precisely.
KANAMARU KAZUAKI
MOCHIZUKI MASAHIKO
WAKO YASUO
