INTERCOMPARISON OF NOBLE METAL THERMOCOUPLES BETWEEN 1000 DEGREES C AND 1600 DEGREES C
Six metrology laboratories of the Member States of the European Community have compared their results in calibrating platinum thermocouples in the temperature range of 100 to 1600 degrees C. Two methods were used: the wire bridge method and the standard pyrometer. The results from the wire bridge method shows that the uncertainty could be +/- 1 degrees C. at the palladium point. Repeated calibrations of a thermocouple may lead to an uncertainty of +/-2 degrees C. For more accurate calibration it is preferable to use primary standard (radiation pyrometer, standard thermocouple). The pyrometric calibration was used by two of the participants (NPL & IMGC). The differences between pyrometer and wire bridge calibration were as high as 10 muV at the gold point and 26 muV at the palladium point. It was shown that part of the difference was due to the thermal gradient in the furnace which is quite different in the two experiments, and part to the inherent uncertainty of the wire bridge method.
Bibliographic Reference: EUR 10351 EN (1986) MF, 170 P., BFR 300, BLOW-UP COPY BFR 850, EUROFFICE, LUXEMBOURG, POB 1003
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Record Number: 1989124082500 / Last updated on: 1987-01-01
Available languages: en