Download - Developments in Metrology
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Developments in Metrology
Ed W.B. de LeerNMi Van Swinden Laboratorium
The Netherlands
UNECE WP.6 Presentation 24 november 2004
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Secondary Standards
SI
Measurand
MeasurementResult
Measurement Process
PrimaryStandard
Calibrated Instrument
s
PrimaryProcedure
Validation,Measurement Uncertainty
Traceability
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Traceability to the SI
Harmonizedlegal regulations
ValidatedMeasurement Methods
Competence of conformity assessment bodies
World Measurement System
NMI´sNMI´s
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Metre Convention
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BIPM
Scientific centre for metrology: custodian of the kilogram and the time
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EUROMET
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CIPM MRA
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Mutual recognition
Mutual recognition of calibration certificates is based on
1. Results obtained in BIPM or regional key comparisons
2. Successful implementation of a quality system based on the principles of ISO/IEC 17025 and, where relevant, ISO Guide 34.The recognition of the QMS can be based on accreditation, peer evaluation or self declaration.In EUROMET, the quality system must be presented in a QS Forum.
Key Comparisons of National Standards
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1 kg Key Comparison
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KCDB
kcdb.bipm.fr
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KCDB
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KCDB
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“High Accuracy” comparisons
All laboratories send a standard to the pilot laboratory
Preparation errors can now be Preparation errors can now be “randomised”“randomised”
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GC-TCD results
GC-TCD Results for 50,000 umol/mol CO in nitrogen
0,93
0,94
0,95
0,96
0,97
0,98
0,99
1,00
1,01
1,02
1,03
47000 47500 48000 48500 49000 49500 50000 50500 51000 51500 52000 52500
Concentration (umol/mol)
Rat
io t
o C
on
tro
l
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GLS for GC-TCD versus Gravimetry
• Conclusions for 50,000 mol/mol– Std dev of residuals is 1mol/mol (0.002% rel)-
after excluding two outliers– At 50,000 mol/mol, the gravimetric values are
very consistent within their stated uncertainties.
-80
-60
-40
-20
0
20
40
60
BAM CENAM CSIRO IPQ KRISS LNE NIST NMIJ NPL
Re
sd
iua
l De
via
tio
n (
um
ol/m
ol)
k=2k=2
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Cu in soil and sediment
0
5
10
15
20
25
30
35
40
45
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0 5 10 15 20 25 30 35 40 45 50
Cu (mg/kg dw, certified value)
Cu
(m
g/k
g d
w,
measu
red
valu
e)
intercept: 0.55 ± 1.28 mg/ kg (k=2)slope: 0.969 ± 0.064 (k=2)
Validation of CRMs with IDMS
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Publication of draft VIM revision
• International Vocabulary in MetrologyApril, 2004
• Revision is based on the Uncertainty Approach (UA) from the GUM. Old version is based on the error concept, which is called the Classical Approach (CA)Conflict with VIML?
• The comments from ISO are approximately 60 text pages
• Uno was not accepted as a new SI unit
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Metrology in short
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GUM revision ?
• No revision of the GUM will be published
• Measurement result = value + measurement uncertainty + unit
• 4 extensions to the GUM are in preparation
• First extension on Monte Carlo calculation of measurement uncertainty published as a draft version
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Metrology and Standardization
• ISO– ISO 17000 (problem: definition of
conformity assessment activities)– ISO 17010 (problem: impartiality question)– MU concept is fully integrated in many new
standards
• CEN– MU concept is fully integrated in many new
standards
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Metrology and Accreditation
• BIPM – ILAC• Certified reference materials are the link to
the SI for most chemical measurements• Accreditation of RM producers is now possible
against ISO/IEC 17025 and ISO Guide 34 in combination
• Special calibrations of NMIs (very low uncertainties)
• Harmonization BMC and CMC• Linking key comparisons to proficiency tests
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From Cooperation to Coordination?
• European Research Area in Metrology (MERA)• Implementing the European Research Area in
Metrology (iMERA)• The metrology dilemma is budget driven:
– Do we serve the national needs in calibration?– Do we manage a profitable business?– Do we serve the future needs in metrology?
• The answer could be in coordination
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Thank you
for your attention