Comparison of the realisation of the ITS-90 over range 83.805 K to 692.677 K

Project Description

The project is expected to be complementary to the CIPM comparison K-3. It is intended to compare any EUROMET NMI realisations of the ITS-90 on the same basis than CIPM interlaboratory comparison. The range of temperature covered in this comparison is from the triple point of Ar (83.805 8 K) through the freezing point of Zn (692,677 K) using long stem SPRTs. Thé comparison will be divided in five loops each of these loops been subpiloted by a laboratory having participated to CIPM K3 comparison (BNM-INM, IMGC, NMi, NPL, PTB) A sixth loop involving these five subpilot laboratories will be coordinated by BNM-INM.
The pilot or subpilot will calibrate 2 SPRTs and circulate one of them. Thé second one been kept for safety. Each sub-pilot will supply a calibrated SPRT of its own to participants belonging to its loop.(see attached document)
Every of the 21 Participants will, therefore, calibrate, at least, one thermometer .The difference between sub-pilot and pilot calibration will be established. So, the calibrations coming from all the participating laboratories will be easily compared. At this juncture, common criteria for calculating uncertainties of calibration will be developed.
If, some fixed points are not available in a participating laboratory , then it may perform the calibration over a limited range.
For SPRT, the method of transfer between the laboratories will be hand-carried. For the countries which are not included in the European Community the participating laboratory must take in charge the customs formalities.

Final Report 2006-09-04

The comparison has been finished and results are published in the KCDB.

Progress Report 2004-03-11

The comparison is divided in five loops each of these loops being subpiloted by a laboratory having participated to CIPM K3 comparison (BNM-INM, IMGC, NMi, NPL, PTB). Each subpilot has provided a selected and calibrated SPRT. All the circulating SPRTs used for the comparison have been calibrated by BNM-INM. The PTB and NMi loops are completed (measurements, reports, stability tests)The NPL, IMGC and SMU loops are in progress. Their advancements are summarized below Subpilot.
Participating laboratories that completed their measurements.
Place of circulating:  SPRT at present time. Participating laboratories that sent the report.
NPL-United Kingdom, JV- Norway, NML- Ireland, EIM - Greece, SMD- Belgium, JV &ndash- Norway, EIM - Greece, IMGC-Italy, IPQ-Portugal, CEM-Spain, BEV &ndash-Austria, METAS- Switzerland, MIRS/FE-LMK - Slovenia, IMGC-Italy, IPQ - Portugal, CEM - Spain, BEV &ndash- Austria (incomplete), METAS - Switzerland,SMU-Slovakia, OMH-Hungary.
At present time 20 participating laboratories have sent their reports and BNM-INM has started to compute the results.A method regarding the analysis of the results has been proposed by BNM?INM and sent to all the participants on February 2004. Some laboratories have passed on their comments on this document to BNM-INM.This BNM-INM working document is intended to be proposed for discussion to the next March Temperature EUROMET contact persons meeting.