intr
oPD
B20
06q
Meeting the need for Intercontinentally Understood Concepts
and corresponding Intercontinentally Agreed Terms in Metrology
(the 2007 edition of the revised 1993 VIM)
Prof Dr P De Bièvre
Independent Consultant
on
Metrology in Chemistry (MiC)
(IRMM 1961-2002)
3rd International Conference on Metrology
TEL AVIV 2006-11-14/15/16
© P De Bièvre TEL AVIV Nov 2006
© P De Bièvre 1999 CITAC SYDNEY Oct 2004: IUPAC-ACD WIEN Feb 2005: KRISS DAEJEON Nov NIMT BANGKOK Nov
NIS AL GIZA Dec MIKES HELSINKI Feb LABQUALITY HELSINKI Feb JSI LJUBLJANA Sep 2006: NPL DELHI FebCARDS ZAGREB Sep HR Metrol Soc ZAGREB Sep 5th HR Congr Medic Biochem POREC Oct
3rd Metrolog Conf TEL AVIV Nov
PD
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136
traceability
What ismetrologicaltraceability ?
PD
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132
Key 1 for MiC: Metrological Traceability (MTr)
Property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty
(proposed in VIM3) (2007) The reference can be
1. a ‘reference quantity value’ carried by a :- a calibrator (measurement standard)
such as carried by (or embodied in) a certified reference material- (the value of) a measurement unit (SI or other)
2. a quantity value obtained by an (internationally) agreed reference measurement procedure - when the measurand operationally defined
A MTr chain to a common reference is a prerequisite for evaluating measurement uncertainty of a measurement result
© P De Bièvre 2001: BUCURESTI – MARIBOR AL QAHERA Sep 2005: KRISS DAEJEON Nov NIMT BANGKOK Nov NIS AL GIZA Dec 2006: NPL DELHI Feb Univ SAO PAULO Jul CARDS ZAGREB Sep HR Metr Soc Sep3rd Metrol Conf TEL AVIV Nov
The establishment of the metrological traceability (chain) of a measurement resultto a‘stated reference’, requires an • a priori knowledge of the measurement procedure (at the stage of planning)
During this process, it is also possible to make an
• a priori estimate of the measurement uncertainty of each link in the metrological traceability chain (thus establishing the structure of uncertainty budget)
© P. De Bièvre 1999 StWEDEN Nov 2002: CERMM-3 ROGASKA Jun 2005: KRISS DAEJEON Nov NIMT BANGKOK Nov NIS AL GIZA Dec KRISS DAEJEON Nov MIKES HELSINKI Feb
LABQUALITY HELSINKI Feb JSI LJUBLJANA Sep 2006: NPL DELHI Feb CARDS ZAGREB SepHR Metrol Soc ZAGREB Sep 5th HR Congress Med Biochem Oct 3rd Metrolog Conf TEL AVIV Nov
PD
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16
PD
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022b
NMI - providedquantity valueorReferencequantity value
a) metrological traceability is establishedb) evaluation of relative measurement uncertainty of measurement result = relative measurement uncertainty of the ratio measurement + relative uncertainty of the “stated reference”
© P De Bièvre GEEL Mar 2002CERMM-3 ROGASKA Jun 2002 AL QAHERA Jan 2003 EILAT NOV 2003 IUPAC-ACD WIEN Feb 2004
MiC BEIJING Oct 2004
PD
B02
022
FieldMeasurement result (quantity value
+ measurement uncertainty)in material X
measurement:unknown / known
known quantity value+ measurement uncertainty
in“stated metrological reference”
relative measurementuncertaintyinmeasurement result
=
relative measurementuncertainty of ratio
+
relative measurementuncertaintyof “stated reference”quantity value of statedmetrological reference
MiC BANGKOK Oct 2004MiC STOCKHOLM Nov 2004 MIKES HELSINKI Feb 2005
JSI LJUBLJANA Sep 2005KRISS DAEJEON Nov 2005
MIKES HELSINKI Feb 2005 NIS AL GIZA Dec 2005 LABQUALITY HELSINKI Feb 2005 NIMT BANGKOK Nov 2005
KRISS DAEJEON Nov 2005 2006: KALPAKKAM FebNPL DELHI Feb Univ SAO PAULO Jul CARDS ZAGREB SepHR Metr Soc ZAGREB Sep XVIII IMEKO RIO Sep3rd Metr Conf TEL AVIV Nov
© P. De Bièvre Sao Paolo Dec 1998 2004: IUPAC-ACD WIEN Feb NIS AL GIZA Dec 2005: KRISS DAEJEON Nov NIMT BANGKOK Nov
2006: NPL DELHI Feb Univ SAO PAULO Jul CARDS ZAGREB Sep HR Metr Soc SepXVIII IMEKO Congr RIO Sep 3rd Metr Conf TEL AVIV Nov
PD
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047
Source: P De Bièvre, Fresenius J Anal Chem 361 (1998) 227 - 234
m (X) / m (K )=
mass values of samples of material X and Y are comparablebecause they are measured in a ratio measurement relative to the
mass K of the common prototype of the common unit kg[note that numerator and denominator being ratio-ed to the same unit,
leads to a numerical value with unit one, symbol 1]
amounts of a specified entity, here of element E in materials X and Y,
are comparable because measured in number N of entities (same unit one) or in same “bunch” of entities (same unit mol)
m (Y) / m (K )m (X)m (Y)
N (E,X) / NA =N (E,Y) / NA
n (E,X)n (E,Y)
=N (E,X)N (E,Y)
R i/j = K i/j . J i/j
© P De Bièvre GEEL Nov 2000 2000: METROLOGIA SAO PAULO Dec2005: GENT Mar JSI LJUBLJANA Sep KRISS DAEJEON Nov
NIMT BANGKOK Nov 2006: NPL DELHI Jan ISMAS MUNNAR Feb KALPAKKAM Feb CCQM SEVRES Apr ICAS 2006 MOSKVA Jun
XVIII IMEKO RIO Sep FZ JUELICH Oct 3rd MET Conf TEL-AVIV Nov
PD
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108
Elements (symbol E) :N (iE)N (jE) =
K (iE+)K (jE+)
. I (iE+)
I (jE+)
= K (iE+, jE+) J (iE+, jE+).
Compounds (symbol Cp) :
N (iCp)N (jCp) =
K (iCp+)K (jCp+)
. I (iCp+)I (jCp+)
Isotopes (symbol iE) :
R i/j = K i/j . J i/j
N (jE) =K (iE+)K (jE+)
. I (iE+)I (jE+) .
We transform the problem of the measurement of a difficult-to-measure quantity
(an amount ratio) into the measurement of an easy-to-measure quantity
(an electric current ratio); the conversion factor K must be measured and its
measurement uncertainty evaluated.
R i/j = K i/j . J i/j
N (iE)
= K (iCp+, jCp+) . J (iCp+, jCp+)
= K (iE+, jE+) . J (iE+, jE+)
R i/j = K i/j . J i/j
© P De Bièvre GEEL Nov 2000 2000: METROLOGIA SAO PAULO Dec2005: GENT Mar JSI LJUBLJANA Sep KRISS DAEJEON Nov
NIMT BANGKOK Nov 2006: NPL DELHI Jan ISMAS MUNNAR Feb KALPAKKAM Feb CCQM SEVRES Apr ICAS 2006 MOSKVA Jun
XVIII IMEKO RIO Sep FZ JUELICH Oct 3rd MET Conf TEL-AVIV Nov
PD
B00
108
Elements (symbol E) :N (iE)N (jE) =
K (iE+)K (jE+)
. I (iE+)
I (jE+)
= K (iE+, jE+) J (iE+, jE+).
Compounds (symbol Cp) :
N (iCp)N (jCp) =
K (iCp+)K (jCp+)
. I (iCp+)I (jCp+)
Isotopes (symbol iE) :
R i/j = K i/j . J i/j
N (jE) =K (iE+)K (jE+)
. I (iE+)I (jE+) .
We transform the problem of the measurement of a difficult-to-measure quantity
(an amount ratio) into the measurement of an easy-to-measure quantity
(an electric current ratio); the conversion factor K must be measured and its
measurement uncertainty evaluated.
R i/j = K i/j . J i/j
N (iE)
= K (iCp+, jCp+) . J (iCp+, jCp+)
= K (iE+, jE+) . J (iE+, jE+)
© P De Bièvre 2004 IUPAC-ACD WIEN Feb 2005: MIKES HELSINKI Feb LABQUALITY HELSINKI Feb JSI LJUBLJANA SepKRISS DAEJEON Nov NIMT BANGKOK Nov NIS AL GIZA Dec 2006: NPL DELHI Feb CARDS ZAGREB Sep
HR Metrol Soc ZAGREB Sep 5th HR Congr Medic Biochem POREC Oct 3rd Metrolog Conf TEL AVIV Nov
PD
B99
136a
uncertainty
What ismeasurementuncertainty ?
© P De Bièvre 1992: Geel 2002: 18th NASTEC NAANTALI Aug 2003: EA-LC TORINO Mar 2004: IUPAC-ACD WIEN Feb MiC BAHRAIN May EURACHEM PRAHA May CITAC BEIJING Oct
MiC HONGKONG Oct 2005: JSI LJUBLJANA Sep 2006: Univ SAO PAULO Jul CARDS ZAGREB SepHR Metr Soc Sep Congr RIO Sep 5th Congr Med Biochem Oct 3rd Metr Conf TEL AVIV Nov
PD
B99
52
Lab 1 and 2:DISCREPANCY
PROBLEM NO PROBLEM
Same measurand in same sample:DISCREPANCY PROBLEMS ARE MOSTLY CAUSED BY LACK OF
FULL ( = ‘GUM’) EVALUATION OF MEASUREMENT UNCERTAINTY (not so much by undetected systematic errors)
Lab 1 and 2:NO DISCREPANCY
Qu
anti
ty v
alu
e o
f m
easu
ran
d
PD
B01
133
Key 2 of MiC: Measurement uncertainty (MU)
is a measure of doubt about the measurement result(not a measure of confidence in a so-called ‘true value’)
1. A measurement uncertainty i.e. the uncertainty of a measurement result, is generated automaticallyfrom the very moment one starts measuring
2. a measurement uncertainty is obtained through an evaluation process:
- type A evaluation of measurement uncertainty- type B evaluation of measurement uncertainty
(calculation only comes after these evaluations)
© P De Bièvre 2001: BUCURESTI - MARIBOR - AL QAHERA Sep 2005: KRISS DAEJEON Nov NIMT BANGKOK Nov : NIS AL GIZA Dec 2006: NPL DELHI Feb CARDS ZAGREB Sep HR Metrol Soc ZAGREB Sep 5th HR Congr Medic Biochem Oct 3rd Metrol Conf TEL-AVIV Nov
© P. De Bièvre 1998 SAO PAULO Dec 2004: SW CHEM SOC STOCKHOLM Nov NIMT BANGKOK Nov2005 MIKES HELSINKI Feb LABQUALITY HELSINKI Feb JSI LJUBLJANA Sep KRISS DAEJEON Nov NIS AL GIZA Dec 2006: NPL DELHI Feb CARDS ZAGREB Sep HR Metrol Soc ZAGREB Sep XVIII IMEKO RIO Sep 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
Key 2 for MiC: Measurement Uncertainty
Type A evaluation of measurement uncertainty:
evaluation of a component of measurement uncertainty by a statistical analysis of measured quantity values obtained under defined measurement conditions
Type B evaluation of measurement uncertainty:
evaluation of a component of measurement uncertainty other than type A evaluation of measurement uncertainty
VIM3 (2007) (proposed)
PD
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43
PD
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134
3. understanding the process called measurement
- is a prerequisite for deciding on the metrological traceability chain of the measurement result- which, in turn, is a prerequisite for the evaluation of measurement uncertainty
4. measurement uncertainty should be small enough for the intended use of the measurement result and need not be smaller (before the measurement is started, it is useful to decide on a target measurement uncertainty inspired by the intended useof the measurement result)
© P De Bièvre 2001 BUCURESTI - MARIBOR - EL QAHIRA Sep 2002: TALLINN Mar 2005: KRISS DAEJEON Nov NIMT BANGKOK Nov NIS AL GIZA Dec 2006: NPL DELHI Feb Feb CARDS ZAGREB Sep
HR Metrol Soc ZAGREB Sep 5th HR Congr Medic Biochem POREC Oct 3rd Metrolog Conf TEL AVIV Nov
© P. De Bièvre SAPUZ Zürich July 1999 2004: MiC STOCKHOLM Nov MIKES HELSINKI Feb 2005: SIST LJUBLJANA Feb JSI LJUBLJANA Sep KRISS DAEJEON Nov NIMT BANGKOK Nov NIS AL GIZA Dec 2006: NPL DELHI Feb 2006 Univ SAO PAULO Jul CARDS ZAGREB Sep HR Metrol Soc Sep 5th HR Congr Medic Biochem Oct 3rd Metr Soc TEL AVIV Nov
PD
B99
85
Measurement results withoutstatements of reliability
(uncertainty) should not be taken seriously
VIM3 (2007) will now require measurement uncertainty to be part of the measurement result by definition
Paul De BièvreAccreditation and Quality AssuranceEditorial, 2 (1997) 269
© P. De Bièvre 1999: HELSINKI June 2001: TrainMiC MARIBOR Oct 2004: INGFOR KØBENHAVN MayMiC BAHRAIN May 2005: J Stefan Inst LJUBLJANA Sep
IMEKO OPATIJA Sep KRISS DAEJEON Nov NIMT BANGKOK Nov NIS AL GIZA Dec 2006: NPL DELHI Feb CITAC MOSKVA Jun Univ SAO PAULO JulCARDS ZAGREB Sep HR Metr Soc Sep 5th Congr Med Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B99
76
‘ON THE AVERAGE THE DUCK WAS DEAD’
A hunter fired two barrels of a shotgun at a duck. The first hits two feet in front, the second hits two feet behind. On the average the duck was dead. What the hunter really wanted was roast duck on the table. In duck hunting one wants to keep trying until a single shot hits the mark. [Source: J Ruzicka 1980 (at the habilitaion of K Heydorn, KØBENHAVN)]
(besides: it must be the first shot, or the duck is gone!)
It is cheaper to perform less measurements, but have sufficiently small measurement uncertainty every time, than making many measurements and use the average
© P. De Bièvre 1999 SAPUZ Zürich July 2005: MIKES HELSINKI Feb LABQUALITY HELSINKI Feb JSI LJUBLJANA Sep KRISS DAEJEON Nov NIMT BANGKOK Nov NIS AL GIZA Dec 2006: NPL DELHI Feb CARDS ZAGREB Sep HR Metrol Soc ZAGREB Sep 5th HR Congr Medic Biochem 3rd Metrolog Conf TEL AVIV Nov
PD
B99
81
ISO/BIPM-Guide to the Expression of Uncertainty in Measurement (GUM)
‘the new approach’
re-establishes the responsibilityof the analyst because
‘evaluation of measurement uncertainty’is a thinking process !
© P De Bièvre 2006 2006: Univ SAO PAULO Jul 5th Croatian Congr POREC Oct 3rd Metr Conf TEL AVIV Nov 2007: CCQM SEVRES Apr
PD
B06
031
From the 1993
International Vocabulary of Basic and General Terms in Metrology
to the 2007
International Vocabulary of Metrology – Basic and General Concepts andassociated Terms in Metrology
PD
B00
121
We have several languages available to communicateabout measurement:
languages
mathematical equations picturessentences.
It follows that we have to attach the same meaning to the same tools.
No wonder that some of the oldest and most needed Commissions of the International Union of Pure and Applied Chemistry (IUPAC) and theInternational Union of Pure and Applied Physics (IUPAP)are Commissions on symbols, nomenclature, units:SUNAMCO for IUPAP, ICTNS for IUPAC.
languages need tools:
symbolspictogrammesterms
© PDB KASTERLEE 2003: Feb 2004: MiC BAHRAIN May EURACHEM PRAHA May CITAC BEIJING Oct MiC HongKong Oct JSI LJUBLJANA 2006: CARDS ZAGREB Sep HR Metrol Soc Sep 5th HR Congr Med Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
© P De Bièvre 2002 KASTERLEE Feb RIO de JANEIRO Apr 2003: EILAT Nov 2004: Traceability KØBENHAVN May MiC BAHRAIN May PRAHA May MiC BEIJING Oct MiC BANGKOK Oct 2005: MIKES HELSINKI Feb KRISS DAEJON Nov NIMT BANGKOK Nov 2006: KALPAKKAM Univ SAO PAULO Jul
CARDS ZAGREB Sep HR Metr Soc ZAGREB Sep XVIII IMEKO Congr Sep 5th HR Congr Medic Biochem POREC Oct 3rd Metr Conf TEL AVIV Nov
PD
B03
043
The revision of ‘VIM2’ (yielding ‘VIM3’):
1. Improved internal consistency
2. Improved consistency of ISO Guides and Standards
3. More clarity which is important because• no clarity, therefore
• no understanding, therefore
• no agreement possible to realize:
- fair trade - implementation of EC Directives - mutual acceptance of measurement results
e.g. in laboratory medicine
PD
B03
044a
The revision of ‘VIM2’ (yielding ‘VIM3’):
4. fully takes on board chemical measurementfor the very first time in history
5. uses the ‘substitution principle’: any concept used in the definition of another conceptmust be replaceable by the definition ofthat concept given elsewhere in the VIM;to make that clear, it is printed in bold
6. uses GUM, even if the definition of some GUM concepts are already up for refinement in ‘GUM2’(which is not yet planned)
© 2002: P De Bièvre KASTERLEE Nov 2003: EILAT Nov 2004: Traceability KØBENHAVN May EURACHEM PRAHA May MiC BEIJING Oct MiC BANGKOK Oct 2005: KRISS DAEJON Nov NIMT BANGKOK Nov MIKES HELSINKI Nov 2006: KALPAKKAM Feb Univ SAO PAULO Jul CARDS ZAGREB Sep
HR Metr Soc ZAGREB Sep 5th HR Congr Medic Bioch POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B03
0352.2
2.6
3.1
3.5
4.0
4.4
4.9
5.3
5.7
6.2
6.6
-50
-40
-30
-20
-10
0
10
20
30
40
50
GlucoseMaterial 1
All reported results (1011) arranged in method groups: Photometry; Amperometry; Vitros 250-950 and Other/No info
IMEP- 17: Trace and minor constituents in human serum
Certified value : 4.412 ± 0.033 mmol·L-1
[U =k ·u c (k =2)]
c Uncertainty Dev.
(mm ol/L) (mmol/L) (%)
7.8 0 77
Values above 50%
Photom etry
© IMEP IRMM 2003 2004: Traceability KØBENHAVN May MiC PRAHA May CITAC BEIJING Oct EURACHEM HONGKONG Oct 2005: LABQUALITY HELSINKI Feb SIST LJUBLJANA Feb JSI LJUBLJANA Sep KRISS KOREA Nov NIMT BANGKOK Nov
2006: CARDS ZAGREB Sep HR Metrol Soc ZAGREB Sep XVIII IMEKO RIO Sep 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
http://www.imep.ws
© P De Bièvre 2003: KASTERLEE 2006: CARDS ZAGREB Sep HR Metrol Soc ZAGREB Sep 5th HR Congr Medic Biochem Oct 3rd Metrol Conf TEL AVIV Nov
PD
B03
041
4.1
4.3
4.5
4.7
4.9
5.1
5.3
5.5
5.7
5.9
6.1
-20
-15
-10
-5
0
5
10
15
20
CholesterolMaterial 1
All reported results (991) arranged in method groups: Photometry, enzymatic; Vitros 250-950 and Other/No info
IMEP- 17: Trace and minor constituents in human serum
Certified value : 5.111 ± 0.021 mmol·L-1 [U =k ·u c (k=2)]
PD
B03
029
1.87
1.96
2.05
2.15
2.24
2.33
2.43
2.52
2.61
2.71
2.80
c
m
mo
l·L
-1
-20
-15
-10
-5
0
5
10
15
20
Dev
iati
on
fro
m t
he
ce
rtif
ied
va
lue
in %
CalciumMaterial 1
Results from all participants (983 laboratories)
IMEP- 17: Trace and minor constituents in human serum
Certified value : 2.334 2 ± 0.006 9 mmol·L-1 [U =k ·u c (k =2)]
c Uncertainty Dev.
(mmol/L) (mmol/L) (%)0.9500 0.00 -59
1.19 0.04 -49
1.27 0.00 -46
1.51 0.06 -35
Values below -20%
c Uncertainty Dev.
(mmol/L) (mmol/L) (%)3 0.00 29
3 0.00 29
3.45 0.12 48
4.41 0.09 89
4.64 0.00 99
4.7 0.08 101
4.75 0.00 103
4.8 0.06 106
4.81 0.00 106
Values above 20%
http://www.imep.ws© IMEP 2003: IRMM 2005: SIST LJUBLJANA Feb 2004: Traceability KØBENHAVN May MiC PRAHA May CITAC BEIJING Oct
EURACHEM HONGKONG Oct 2005: MIKES HELSINKI Feb LABQUALITY HELSINKI Feb JSI LJUBLJANA Sep KRISS DAEJEON Nov NIMT BANGKOK Nov NIS AL GIZA Dec 2006: NPL DELHI Feb CARDS ZAGREB Sep HR Metrol Soc ZAGREB Sep
5th HR Congr Medic Biochem POREC Oct 3rd Metrolog Conf TEL AVIV Nov
© P De Bièvre KASTERLEE 2003
PD
B20
0303
0
3.36
3.44
3.51
3.59
3.66
3.74
3.81
3.88
3.96
4.03
4.11
c
mm
ol·L
-1
-10
-8
-6
-4
-2
0
2
4
6
8
10
De
viat
ion
fro
m t
he
cert
ifie
d v
alu
e in
%
PotassiumMaterial 1
Results from all participants (999 laboratories)
IMEP- 17: Trace and minor constituents in human serum
Certified value :3.735 ± 0.021 mmol·L-1 [U =k ·u c (k =2)]
c Uncertainty Dev.
(mmol/L) (mmol/L) (%)
5.68 0.06 52
Values above 10%
© P De Bièvre KASTERLEE 2003
PD
B20
0331
0.0
56.8
113.6
170.4
227.2
-100
0
100
200
300
AmylaseMaterial 1
Results from all participants (863 laboratories)
IMEP- 17: Trace and minor constituents in human serum
Certified value : 56.8 ± 2.6 U·L-1
[U =k ·u c (k=2)]
1 v alue above 300%
© IMEP 2003 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B20
0332
0.0
56.8
113.6
170.4
227.2
- 100
0
100
200
300
AmylaseMaterial 1
All reported results (863) arranged in method groups: IFCC comparable methods; Different methods, Scandinavian level;
Different methods, Roche level; Different methods, Original level; Vitros 250-950, calculated to IFCC; Vitros 250-950, Scandinavian level; Vitros 250-950, calculated to Roche level;
Vitros 250-950, original level and Other/No info
IMEP- 17: Trace and minor constituents in human serum
Certified value : 56.8 ± 2.6 U·L-1
[U=k·u c (k =2)]
1 value above 300%
© IMEP 2003 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B20
0333
37.3
44.7
52.2
59.7
67.1
74.6
82.0
89.5
96.9
104.4
111.9
-50
-40
-30
-20
-10
0
10
20
30
40
50
CreatinineMaterial 1
Results from all participants (1022 laboratories)
IMEP- 17: Trace and minor constituents in human serum Certified value : 74.57 ± 0.57 µmol·L-1 [U=k·u c (k =2)]
c Uncertainty Dev.
(µmol/L) (µmol/L) ( %)0.38 0 -99
Values below -50%
c Uncertainty Dev.
(µmol/L) (µmol/L) ( %)114.92 17.68 54
119.20 10.37 60
Values above 50%
© IMEP 2003 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B20
033437.3
44.7
52.2
59.7
67.1
74.6
82.0
89.5
96.9
104.4
111.9
-50
-40
-30
-20
-10
0
10
20
30
40
50
IMEP- 17: Trace and minor constituents in human serum Certified value : 74.57 ± 0.57 µmol·L-1 [U=k·uc (k =2)]
All reported results (1022) arranged in method groups: Photometry, enzymatic; Photometry, Jaffe; Vitros 250-950; Vitros DT60 and Other/No info
CreatinineMaterial 1
c Uncertai nty Dev.
(µmol/L) (µmol/L) (%)0.38 0 -99
Values below -50%
Photomet ry , Jaffe
c Uncertainty Dev.
(µmol/L) (µmol/L) (%)114.92 17.68 54
119.20 10.37 60
Values above 50%
Photometry , Jaffe
© IMEP 2003 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B20
0336
13.9
18.0
22.2
26.4
30.5
34.7
38.9
43.0
47.2
51.4
55.5
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
-Glutamyl transferaseMaterial 1
Results from all participants (950 laboratories)
IMEP- 17: Trace and minor constituents in human serum
Certified value : 34.70 ± 0.93 U·L-1
[U=k ·u c (k=2)]
© IMEP 2003 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B20
0337
13.9
18.0
22.2
26.4
30.5
34.7
38.9
43.0
47.2
51.4
55.5
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
-Glutamyl transferaseMaterial 1
All reported results (950) arranged in method groups: IFCC comparable methods; GLUCANA-Tris, original level; GLUNA, original level; Vitros 250-950 and Other/No info
IMEP- 17: Trace and minor constituents in human serum
Certified value : 34.70 ± 0.93 U·L-1
[U=k·u c (k =2)]
© IMEP 2003 2004: Traceability KØBENHAVN May MiC PRAHA May CITAC BEIJING Oct EURACHEM HONGKONG Oct 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B20
0303
8
17.4
20.8
24.3
27.8
31.2
34.7
38.2
41.6
45.1
48.6
52.1
-50
-40
-30
-20
-10
0
10
20
30
40
50
Results from participants from Nordic Countries;Denmark, Finland, Iceland, Norway and Sweden
IMEP- 17: Trace and minor constituents in human serum
Certified value : 34.70 ± 0.93 U·L-1
[U =k ·u c (k=2)]
-Glutamyl transferaseMaterial 1
http://www.imep.ws
© IMEP 2003 2006: 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B20
0340
17.4
20.8
24.3
27.8
31.2
34.7
38.2
41.6
45.1
48.6
52.1
c
U
·L-1
-50
-40
-30
-20
-10
0
10
20
30
40
50
Dev
iati
on
fro
m t
he
cer
tifi
ed v
alu
e in
%
-Glutamyl transferaseMaterial 1
Results from participants from Asia-Pacific; Australia, China and New Zealand
IMEP- 17: Trace and minor constituents in human serum
Certified value : 34.70 ± 0.93 U·L-1 [U =k ·u c (k =2)]
PD
B05
010
© P De Bièvre Feb 2005
http://irmm.jrc.be/html/
interlaboratory_comparisons/imep/
index.htm
‘IMEP’‘REIMEP’ ‘NUSIMEP’
© P De Bièvre 2004 INGFOR KOEBENHAVN May 2005: KRISS DAEJEON Nov NIMT BANGKOK Nov NIS AL GIZA Dec 2005: MIKES HELSINKI Feb LABQUALITY HELSINKI Feb JSI LJUBLJANA Sep KRISS DAEJEON Nov 2006: NPL DELHI Feb CARDS ZAGREB Sep
HR Metrol Soc ZAGREB Sep 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B05
003
Measurement uncertainty and sampling uncertainty,one more example of ambiguity:
Does sampling uncertainty contribute tomeasurement uncertainty?
that depends on the definition of the measurandwhich then influences the measurement procedure
Source: Provetagning, Metrologi, Kemometri: den STORE sammenheng INGFOR KØBENHAVN 2004-05-04
C IRMM 2000: GEEL Dec 2005: JSI LJUBLJANA Sep 2006: Univ SAO PAULO Jul CARDS ZAGREB Sep HR Metr Soc Sep XVIII IMEKO RIO Sep 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B01
015
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
0.60
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20Accredited (self-declaration)
Non-accredited (self-declaration)
No statement by participant
Pb
Results from all participants according to the self-declared accreditation status for this element.
IMEP- 13 : Trace elements in polyethylene
Certified range [U=k·uc (k=2)]: 0.501 - 0.539 mmol·kg-1
2 'less than' value
Accredited 1
Non-accredited 3
Values above 20%
0.00
0.05
0.10
0.15
0.20
0.25
0.30
0.35
0.40
0.45
0.50
0.55
c
mm
ol·
kg-1
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
Dev
iati
on
fro
m c
entr
e o
f re
fere
nce
ran
ge
in %
Experienced laboratory (self-declaration)
Less experienced laboratory (self-declaration)
Non experienced laboratory (self-declaration)
No statement by laboratory
Pb
Results from all participants.
IMEP- 10 : Trace Elements in Polyethylene
Certified reference range [U =k ·u c (k=2)]: 0.449 - 0.491 mmol·kg-1
PD
B99
36d
example of TMU of 15%around Reference Range
1
2
2
3
3
4
5
© IMEP 1999 Orlando Feb 2002: PORTOROZ Sep AL QAHERA Jan 2004: IUPAC-ACD WIEN Feb BAHRAIN May EURACHEM PRAHA May MiC BANGKOK Oct 2005: SIST LJUBIJANA Feb KRISS DAEJEON Nov
NIMT BANGKOK Nov NIS AL GIZA Dec JSI LJUBLJANA Sep 2006: NPL DELHI Feb CARDS ZAGREB Sep HR Metrol Soc Sep XVIII IMEKO RIO Sep 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
© IMEP 2003 2006: 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B04
004-
08
Results
0.0
0.4
0.8
1.2
1.6
2.0
2.4
2.8
3.2
3.6
4.0
4.4
4.8
5.2
5.6
6.0
6.4
6.8
7.2
7.6
8.0
8.4
8.8
9.2
9.6
c
m
g·k
g-1
-100
-90
-80
-70
-60
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
De
via
tio
n f
rom
th
e c
ert
ifie
d v
alu
e i
n %
Yes NoAs
Results from all participants on the use of Certified Reference Materials. (CRMs)
IMEP- 20: Trace elements in Tuna Fish Certified value : 4.93 ± 0.21 mg·kg-1 [U=k·u c(k=2 )]
.
Value above 100%
Yes 0
No 1
Less than values
Yes 0
No 4
GEEL Dec 2000
PD
B01
003
IMEP-9 trace elements in water
CCQM-K2
LGC
VNIIM
LNE
IRMMNRCIRMMKRISSNIMCPTB NMi
NIST
31
36
41
46
51
56
61
66
71
76
81
86
91
-50
-40
-30
-20
-10
0
10
20
30
40
50
result with uncertainty statement with uncertainty budget
result with uncertainty statement without uncertainty budget
CCQM-9: key comparison Pb in waterCertified range (±U=2uc): 61.0 - 63.6 nmol·L-1
Pb
EUROMETAoS 332
PTBNMI LNE
LGC
LGC
31
36
41
46
51
56
61
66
71
76
81
86
91
-50
-40
-30
-20
-10
0
10
20
30
40
50
EUROMET- AoS Project 332 members participating in IMEP-9
Certified range (±U=2u c): 61.0 - 63.6 nmol·L-1
Pb
Results from EUROMET laboratories.
AustriaJapan
Canada
31
36
41
46
51
56
61
66
71
76
81
86
91
-50
-40
-30
-20
-10
0
10
20
30
40
50
IMEP- 9 : Trace elements in Water
Certified range (±U =2u c): 61.0 - 63.6 nmol·L-1
Pb
Results from laboratories in Switzerland.
1 'less than' value
31
36
41
46
51
56
61
66
71
76
81
86
91
-50
-40
-30
-20
-10
0
10
20
30
40
50
IMEP- 9 : Trace elements in Water
Certified range (±U=2u c): 61.0 - 63.6 nmol·L-1
Pb
Results from all laboratories.
10 'less than' values4 values below -50%
18 values above 50%
one material
© P De Bièvre 2001 2006: 5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B01
127
Describing measurement results a posteriori (the ‘culture’ of statistics in chemical measurement)
only describes a result in terms of a distributionof a set of values a posteriori
Establishing the authority of a measurement result, can be done a priori :
by deciding the metrological traceability chain;
it can/must be done before the measurement
© P De Bièvre 2005 KASTERLEE Jan 2005: KRISS DAEJEON Nov 2006: CARDS ZAGREB Sep HR Metrol Soc ZAGREB Sep
5th HR Congr Medic Biochem POREC Oct 3rd Metrol Conf TEL AVIV Nov
PD
B05
001
“Life can only be understood‘BACKWARDS’,
but it must be livedFORWARDS”
S. KierkegaardDanish philosopher
1813 - 1855
© P De Bièvre SAPUZ ZÜRICH July 1999 2002: NASTEC NAANTALI Aug 2005: IMEKO OPATIJA Sep NIMT BANGKOK Nov KRISS DAEJEON Nov NIS AL GIZA Dec 2006: NPL DELHI Feb KALPAKKAM FebCITAC MOSKVA Jun SAO PAULO Jul ZAGREB Sep IMEKO RIO SepPOREC Oct MET CONF TEL-AVIV Nov
PD
B99
121
The task is to demonstrate the scientific authority of the result of the measurement.
This needs underpinning (‘Untermauerung’) of the measurement result
in order to lead to the necessary credibility.
PD
B01
144
Metrology in chemistry:The Hubble telescope ...
= the ‘spectacles’ of the analytical chemist
BEFORE AFTER
© P Taylor GEEL Sep 1999 2004: MiC BEIJING Oct MiC BANGKOK Oct 2005: MIKES HELSINKI Feb LABQUALITY HELSINKI Feb SIST LJUBLJANA Feb JSI LJUBLJANA Sep KRISS DAEJEON Nov NIMT BANGKOK Nov
2006: KALPAKKAM Feb CITAC MOSKVA Jun SAO PAULO Jul ZAGREB Sep IMEKO RIO POREC Oct 3rd MET Conf TEL-AVIV Nov