JPS6428520A - Measuring jig - Google Patents

Abstract

PURPOSE:To improve temperature measuring accuracy at low temperatures, by thermally connecting a lead wire of a temperature measuring jig or a temperature measuring element with that which has equivalent or equal temperature distribution and thermal capacity with the jig or the element. CONSTITUTION:When the gas temperature of a piping 1 in which cooling gas is flowing is to be measured, a copper block 4 having an opening is mounted on the piping 1. A temperature sensor 5 is inserted in the copper block 4. Moreover, a similar copper block 4 is mounted in the upper stream of the piping 1, in which a dummy temperature sensor 6 is inserted. A heater 7 is attached to the upper block 4 at the side opposite to the piping 1. A thermoelectric couple 8 is installed at the same positions of the blocks 4. A lead wire 9 coming from the temperature sensor 5 is wound around the dummy block 4. Then, the current to the heater 7 is controlled by the thermoelectric couple 8 so that the temperatures in both blocks are 0 respectively. Accordingly, no heat invades into an object to be measured from outside through the lead wire 9, thereby improving the temperature measuring accuracy.