Automatic equipment for calibrating platinum-platinorhodium thermocouples
- 20 Downloads
The above automatic equipment is universal. It provides if required direct measurements of the reference and tested thermocouples' thermal emfs, or measurements according to the electrode by electrode comparison method outlined in .
The equipment provides simultaneous calibration of 4–5 platinum-platinorhodium thermocouples under dynamic conditions in 40–50 min.
It uses for calibrating and checking thermocouples a reference thermocouple which is of the same type as the tested one but of a higher grade. It is therefore possible to calibrate by means of this equipment platinorhodium thermocouples type PR 30/6. It can also be used for checking industrial thermocouples of the chromel-alumel and the chromelcopel types, providing a similar type thermocouple is used as the variable measure of the thermal emf.
The automatic equipment provides a direct reading of ΔEt=E1−E2 as a function of temperature, in the form of a continuous curve. Hence, it is not necessary to calculate calibration data by means of influence functions  when checking Grade 2 platinum-platinorhodium thermocouples.
Tests of a laboratory model of this equipment have shown that the error in calibrating platinum-platinorhodium thermocouples does not exceed ±6 mv over the entire temperature range of 300–1200°C.
The maximum discrepancy in the calibration results obtained on the automatic equipment and those obtained by the electrode by electrode method of calibration and by direct measurements of the tested and reference thermocouples' thermal emfs by means of the normal laboratory equipment did not exceed ±5μv.
KeywordsComparison Method Maximum Discrepancy Calibration Data Laboratory Model Continuous Curve
Unable to display preview. Download preview PDF.
- 1.T. M. Dauphinee, An apparatus for comparison of thermocouples. Canad. J. Phys, No. 6, 33 (1955).Google Scholar
- 2.T. V. Voevoda, Izmeritel'naya tekhnika, No. 5 (1957).Google Scholar
- 3.I. V. Butusov, Priborostroenie, No. 10 (1959).Google Scholar
- 4.A. I. Kasperovich, Izmeritel'naya tekhnika, No. 5 (1959).Google Scholar
- 5.B. K. Bragin, Izmeritel'naya tekhnika, No. 2 (1955).Google Scholar
- 6.Temperature Measuring Instruments and Their Testing (Instruction Data) [in Russian], Standartgiz, M.(1957).Google Scholar