MRA Appendix B

This page contains a collection of old key / supplementary comparison data. The content is not necessarily up-to-date anymore.

An officially maintained list of EURAMET TC-L comparisons with results can be found at the BIPM website.

CCL key comparisons (CCL-Kx)

First round of  Key Comparisons, authorised by the CCL.

CCL-K1Gauge blocksCompleteFinal report
CCL-K2Long gauge blocks/length barsCompleteFinal report
CCL-K3PolygonsCompleteFinal report
CCL-K4Ring & plug gaugesCompleteFinal report
CCL-K51D CMM artefactsCompleteFinal report
CCL-K62D CMM artefactsCompleteFinal report

Second round of  Key Comparisons, authorised by the CCL.
(Not all future comparisons follow the classical scheme, some are operated as inter-RMO comparisons).

CCL-K1.2009Gauge blocks up to 500 mmPlanning -


CCL NANO pilot studies (NANOx)

Official pilot studies using MRA guidelines, authorised by the CCL.

NANO1Photomask linewidthStarts soon -
NANO2 (CCL-S2)Step heightCompleteFinal report
NANO3 (CCL-S3)LinescalesCompleteFinal report
NANO4 (CCL-S1)1D gratingsCompleteFinal report
NANO5 (CCL-S4)2D gratingsCompleteFinal report
NANO6SPM linewidthStarts soon -


EURAMET key comparisons (EURAMET.L-Kx)

New key comparisons organized by EURAMET's TC Length and designed to link to corresponding CCL key comparisons.

Number Subject Project No. Status / Report
EUROMET.L-K1 Gauge blocks 471 Final report
EUROMET.L-K1.1 Gauge blocks 634 Final report
EUROMET.L-K1.2 Gauge blocks 1138 Final report
EUROMET.L-K2 Long gauge blocks 602 Final report
EURAMET.L-K1.2011 Gauge blocks (up to 500 mm) 1218 Final report
EUROMET.L-K3.1 Optical polygons 870 Final report
EUROMET.L-K3.2009 Autocollimators 1074 Final report
EUROMET.L-K4.2005 Ring & plug gauges 812 Final 1
Final 2
EUROMET.L-K5-2004 1D CMM artefacts 777 Final report
EUROMET.L-K6 2D CMM artefacts 743 Final report
EUROMET.L-K7.2006 Linescales (up to 100 mm) 882 Final Report
(not approved)
EUROMET.L-K8 Roughness 1003 Final report
EURAMET.L-K8.2013 Key comparison on surface roughness standards 1245 Final report



EURAMET supplementary comparisons (EURAMET.L-Sx)

Previous and new comparisons organized and reviewed by EURAMET TC-Length as being suitable for supporting the MRA.

Number Subject Project No. Status / Report
EUROMET.L-S1 Linescales 252 BNM/LNE, 1995
EUROMET.L-S2 Thermal expansion of gauge blocks 275 Metrologia paper
Final report
EUROMET.L-S3 Depth setting standards 301 Final report
EUROMET.L-S4 Wires (diameter) 308 Final report
EUROMET.L-S5a Roundness BCR Final report
EUROMET.L-S5b Roundness 361 Final report
EUROMET.L-S6 Thermal expansion of long gauge blocks 390 PTB report
EUROMET.L-S7 Surface plates BCR EUR 14059 EN, 1992
EUROMET.L-S8 Nd YAG lasers Bilateral Final report
EUROMET.L-S9 Grid plates BCR 3442 3442/1/0/189/91/7
EUROMET.L-S10 Squares 570 Final report
EUROMET.L-S11 Surface texture 600 Metrologia paper
Final report (6MB)
EUROMET.L-S12 Gauge blocks by comparison 601 Final report
EUROMET.L-S13 Cylindrical artefacts 369 Final report (PTB)
EUROMET.L-S14 Steel tapes 677 Final report
EUROMET.L-S15 Step height standards by SPM 707 Final report
EUROMET.L-S15a Step height standards by SPM 925 Final report
EUROMET.L-S16 Gauge blocks by comparison 797 Final report
EUROMET.L-S17 Steel tape, trilateral (link to S14) 875 Final report
EUROMET.L-S18 Granite square, bilateral (link to S10) 905 Final report
EUROMET.L-S19 Steel cylindrical square, bilateral (link to S10) 910 Final report
EURAMET.L-S20 Laser distance measuring instruments 1169 Final report
EURAMET.L-S21 Thread pitch 1223 Final report
EURAMET.L-S22 Gauge blocks by comparator 1254 Final report
EURAMET.L-S23 Roundness by multi-step 1269 Final report
EURAMET.L-S25 Comparison of pocket-type laser distance measurement instruments 1354 Final report
EURAMET.L-S26 Measurement of groove depth standard in the range μm up to 1 mm 1407 Final report



EURAMET/EUROMET bi-lateral comparisons

Bilateral comparisons, not necessarily registred to MRA KCDB.

NumberSubjectProject No.Status
NoneIndexing tables 725Final report



Previous EUROMET key comparisons (EUROMET.L-Kx.PREV)

Existing Comparisons in the same subjects as the CCL-Kx series, reviewed by EUROMET Length as being suitable for the interim MRA.

Number Subject Project No. Report
EUROMET.L-K1.PREV Gauge blocks 229 Final report
EUROMET.L-K2.PREV Long gauge blocks/length bars 254 Final report
EUROMET.L-K3.PREV Polygons 371 Final report (PTB)
EUROMET.L-K4.PREV Ring & plug gauges 384 Final report
EUROMET.L-K5.PREV Step gauge 372 Final report (PTB)