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Toward more accurate temperature fixed points

Project Description

a) Objectives
As it was presented during the last Euromet meeting, the last Key Comparisons in Temperature made appear the necessity of developing more accurate temperature fixed points in the Europe.
The laboratories interested in participating to this activity are invited to share this large task.

b) Description of the work
The project will be organised in two types of Working Packages for covering the fields of activities: to be realistic the objectives of the project must be limited. It is suggested to involve in a first step the range covered by Long Stem Platinum Resistance Thermometer (Argon triple point to Silver freezing point).

General studies:

  • Effects of impurities on highest purity available
  • Chemical analysis of the initial substance
  • Chemical analysis of the substance after been used for a while
  • Chemical analysis of the crucible
  • Effects of isotopic composition
  • Control of the thermal process
  • Design of the cell
  • Comparison between open and sealed cell
  • Studies on specific temperature fixed point

The participating laboratories will be able to focus their activity in studying specific temperature fixed points. This activity will be coordinated to avoid unnecessary duplication

c) Milestones and expected results
The coordinated efforts are expected to lead to a better understanding of the pending difficulties and therefore open the possibility of getting a better accuracy of the ITS-90 realisation in Europe.
By the end of 2003, a questionnaire has been drawn up and sent to the EUROMET laboratories by BNM-INM. From the answers of the laboratories a preliminary list of existing facilities, able to be involved in the development of this project , has been established by BNM-INM.
This document will be presented at the next EUROMET meeting (March 2004) in order to be used as a starting point for an exchange of ideas. The details of this project will be established from the results of the discussion; in particular the list of participant laboratories involved in the different steps of this project will be set up.

The project is covering a large spectrum of activities and a large domain of temperature, as well. Significant results are expected to be obtained within a while of several years.

Final Report 2011-03-15

The project has been completed and the report can be downloaded here>>

Progress Report, 2005-03-11

A Kick-off meeting was organised in connection with the last TEMPMEKO meeting in Croatia (June 2004). It was agreed by the participants to distribute the project in Working Packages for covering the fields of activities. It was decided to restrict the project to the temperature fixed points associated with Long Stem Platinum Resistance Thermometers (argon triple point to silver freezing point).

11 Working Packages were identified. 9 Working Packages (WPs) are devoted to one particular fixed point. It was decided, during the kick off meeting, to include a WP on the TPW.

Every WP is piloted by a specific laboratory and can involve several participating labs.

Working Subject Pilot Working Subject Pilot Working Subject Pilot package package package WP1 Ar FR WP5 In DE WP9 Ag FR WP2 Hg FR WP6 Sn UK WP10 Chemical WP3 TPW NL WP7 Zn DE analysis IT WP4 Ga SK WP8 Al FR WP11 Collect knowledge UK

Working package Subject Pilot Working package Subject Pilot Working package Subject Pilot
WP2 Hg FR WP6 Sn UK WP10 Chemical analysis IT
WP3 TPW NL WP7 Zn DE WP11 Collect knowledge UK
WP4 Ga SK WP8 Al FR -    

CNAM-INM drew up a “Project Workplan”. It was sent to the pilots in March 2005 for comments.

A workshop about this “Project Workplan” is intended during the next EUROMET meeting in Vienna (7 April 2005).


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