to BIPM.org
CIPM MRA PARTICIPANTS
All data listed in the KCDB have been reviewed and approved within the CIPM Mutual Recognition Arrangement
Menu
Login
CIPM MRA PARTICIPANTS
CMC statistics
Comparison
Comparison close
Results
print out

MEASURAND : Central length of long gauge blocks measured by interferometry according to ISO 3650; gauge block material: steel

NOMINAL VALUES : 6 gauge blocks from 150 mm to 900 mm, including three different 500 mm gauge blocks and two different 900 mm gauge blocks

Degrees of equivalence, Di and expanded uncertainty Ui, of each laboratory i with respect to the reference value for each gauge block k (k = 1 to 6), expressed in nm

L1 = 150 mm, S/N 8728

L2 = 500 mm, S/N AA/71001

L3 = 500 mm, S/N 500 B

L4 = 900 mm, S/N EM/718

L5 = 500 mm, S/N 4 PTB 55

L6 = 900 mm, S/N PTB 5.13 11/2001

Note: UVMT/VMC = 1379 nm for L6 = 900 mm, S/N PTB 5.13 11/2001

Comparison
Comparison close
Results
print out

MEASURAND : Central length of long gauge blocks measured by interferometry according to ISO 3650; gauge block material: steel

NOMINAL VALUES : 6 gauge blocks from 150 mm to 900 mm, including three different 500 mm gauge blocks and two different 900 mm gauge blocks

Degrees of equivalence, Di and expanded uncertainty Ui, for each nominal length.

Results are presented under A4 printable format in Summary Results (.PDF file).

Comparison
Comparison close
RMO comparison
Linked comparison
EUROMET.L-K2
print out
Metrology area, Sub-field Length, Dimensional Metrology
Description Long gauge blocks from 150 mm to 900 mm
Time of measurements 2002 - 2005
Status Approved for equivalence
Final Reports of the comparisons
Metrologia, 2006, 43, Tech. Suppl., 04003
Measurand Central length: 150 mm, 500 mm and 900 mm
Transfer device Six steel gauge blocks
Comparison type Key Comparison
Consultative Committee CCL (Consultative Committee for Length )
Conducted by EURAMET (European Association of National Metrology Institutes)
RMO Internal Identifier EUROMET Project No 602
Comments

Results published on 02 May 2006

Long gauge blocks by interferometry
Pilot institute NPL
National Physical Laboratory
United Kingdom
Contact person Andrew Lewis

+44 (0) 20 8943 6074
First Name Last Name
wwww@ww.www +356719836 Institute 1 Institute 1 Khmelnitskiy
Pilot laboratory
NPL

National Physical Laboratory, United Kingdom, EURAMET

BEV

Bundesamt für Eich- und Vermessungswesen, Austria, EURAMET

CEM

Centro Español de Metrologia, Spain, EURAMET

CMI

Czech Metrology Institute, Czechia, EURAMET

GUM

Glowny Urzad Miar, Central Office of Measures, Poland, EURAMET

INM

National Institute of Metrology, Romania, EURAMET

INRIM

Istituto Nazionale di Ricerca Metrologica, Italy, EURAMET

IPQ

Instituto Portugues da Qualidade, Portugal, EURAMET

LNE

Laboratoire national de métrologie et d'essais, France, EURAMET

METAS

Federal Institute of Metrology, Switzerland, EURAMET

MIKES

VTT Technical Research Centre of Finland Ltd, Centre for Metrology/Mittatekniikan keskus, Finland, EURAMET

PTB

Physikalisch-Technische Bundesanstalt, Germany, EURAMET

SMD

Service de la Métrologie Belge, Belgium, EURAMET

SMU

Slovensky Metrologicky Ustav, Slovakia, EURAMET

UME

TÜBITAK Ulusal Metroloji Enstitüsü, Türkiye, EURAMET

Comparison
Comparison close
Results
print out

MEASURAND : Central length of long gauge blocks measured by interferometry according to ISO 3650; gauge block material: steel

NOMINAL VALUES : 6 gauge blocks from 150 mm to 900 mm, including three different 500 mm gauge blocks and two different 900 mm gauge blocks

The EUROMET key comparison reference value, xRk, for each gauge block k is obtained from the weighted mean xwk (with weights wik based on each reported uncertainty) of the participants' values xik by adding a constant Ck chosen such that the reference value is the nominal length: xRk = Lk = xwk + Ck.
The standard uncertainty uRk of xRk is obtained from the reported standard uncertainties uik.  Outliers are excluded from the weighting, based on the Birge ratio testing. Further information on the computation of xRk and uRk is given in Section 8 of the Final Report.

The degree of equivalence of each laboratory with respect to the reference value for each gauge block k is given by a pair of terms: the difference Dik and its expanded uncertainty Uik (coverage factor: 2) with
Dik = (xik + Ck) - xRk = xik - xwk and Uik = 2(uik2 - uRk2 + uAk2)1/2 where uAk is the artefact uncertainty, which takes into account uncorrelated errors including instability of the artefact.

The calculation of the degree of equivalence between two laboratories i and j is not recommended for comparisons involving several material standards, since it cannot be expressed with a single pair of terms. It would have to be calculated separately for each gauge block k and would then be given by a pair of terms:
the difference Dijk and its expanded uncertainty Uijk (coverage factor: 2).
Dijk = xik - xjk and Uijk = 2(uik2 + ujk2)1/2

Key comparison EUROMET.L-K2 is parallel to key comparison CCL-K2. Numerical linking of these comparisons is not recommended due to artefact dependent offsets. Instead, laboratories participating competently in both key comparisons establish the link and assure equivalence.

Comparison
Comparison close
Results
print out

MEASURAND : Central length of long gauge blocks measured by interferometry according to ISO 3650; gauge block material: steel

NOMINAL VALUES : 6 gauge blocks from 150 mm to 900 mm, including three different 500 mm gauge blocks and two different 900 mm gauge blocks

xik : result of measurement carried out by laboratory i for gauge block k with nominal length Lk, expressed as the deviation from nominal length in nm
uik : combined standard uncertainty of xik reported by laboratory i

Results of IPQ were withdrawn by the laboratory as not representative of their instrument, which was still being developed.