Intercomparison of the freezing point of Indium

Project Description

A co-operation between Institut National de Métrologie (FR) and Justervesenet (NO) is undertaken to carry out this project. One transfer indium cell together with one furnace will be circulated to the participating laboratories in order to be intercompared with the local realization of the freezing point of indium.

The main objective with this intercomparison is to establish the agreement between the results from different participating laboratories, to clear up the possible discrepancies and to develop an improved procedure for realization and determination of the freezing point of indium.

The intercomparison measurements will consist of one set of freezing point determinations on the circulating cell and one set of measurements on the local cell(s).

The results of this project will enable exploiting the In freezing point for realisation of ITS-90 with highest precision in the very important range 0 °C to 156 °C and to gain experience with measurements at the indium freezing point.

If the laboratories will use one calibrated thermometer to perform the measurements, the results will permit to examine the agreement between the measured value at Indium freezing point and the calculated values from the calibration at water triple point and the freezing point of Tin and Zinc.

Final report 2008-01-31

The project has been completed and the results are available in the KCDB.