Intercomparison on the use of microcrucibles for the calibration of thermocouples (collection of individual reports)Funded under: FP2-BCR 4
Five years ago INM developed microcells allowing an in situ thermocouple calibration process in the actual temperatures field without modifying the mechanical feature of the thermocouple. In order to assess the feasibility of the use of these microcrucibles for the calibration of type S thermocouples, it was decided to intercompare the results of the calibration of a type S thermocouple at the silver point (961.78 C) by using an INM microcrucible, with those obtained by using the routine standard calibration procedure in different national laboratories. This synthesis report presents the results of the measurements performed at these laboratories. A batch of twelve microcells was manufactured and filled with pure silver at INM prior to being characterised. The emf values developed by a type S thermocouple when immersed into each microcell are compared to those obtained when immersed into a large classical silver cell and the uncertainties of the measurements are indicated. Each participating laboratory received its own microcell and undertook a similar comparison between the responses of a thermocouple in microcell and large cell. The discrepancies between results spread over a 0.17 C range, consistent with the budget of uncertainties, and can be explained by the lack of homogeneity of the thermocouples. This report suggests microcells are able to perform calibration of thermocouples within the limits of their practical stability.
Bibliographic Reference: EUR 14537 EN (1992) 120 pp., MF, ECU 8
Record Number: 199211417 / Last updated on: 1994-11-29
Original language: en
Available languages: en