Comparison
Comparison close
Results

BIPM.RI(II)-K1.Co-58 and APMP.RI(II)-K2.Co-58

MEASURAND : Equivalent activity of 58Co

Degrees of equivalence Di and expanded uncertainty Ui (k = 2) expressed in MBq



Red diamonds and black square: participants in BIPM.RI(II)-K1.Co-58 (the black square identifies the participant result prior to 1983)
Blue circles: participants in APMP.RI(II)-K2.Co-58 only

The APMP.RI(II)-K2.Co-58 results were reported in year 2000.

Comparison
Comparison close
Results

BIPM.RI(II)-K1.Co-58 and APMP.RI(II)-K2.Co-58

MEASURAND : Equivalent activity of 58Co

   
Lab iDiUi
 / MBq/ MBq
CMI-IIR-0.140.21
OMH-0.050.11
NPL0.010.21
BNM-LNHB0.140.08
PTB0.020.11
NMIJ0.030.13
   
BARC0.290.34
CNEA0.130.31
INER0.090.29
KRISS0.070.10
LNMRI0.500.25
NIM-0.040.20

In blue: participants in APMP.RI(II)-K2.Co-58 only

The full matrix of equivalence is available in Summary Results (summary of the results of both comparisons as a .PDF file).

Comparison
Comparison close
BIPM comparison
Linked comparison
BIPM.RI(II)-K1.Co-58
Metrology area, Sub-field Ionizing Radiation, Section II (Measurement of Radionuclides)
Description Activity of radionuclide Co-58
Time of measurements 1978 -
Status Continuous, approved for equivalence
Final Reports of the comparisons
Measurand SIR equivalent activity
Transfer device Radioactive solution
Comparison type Key Comparison
Consultative Committee CCRI (Consultative Committee for Ionizing Radiation)
Conducted by BIPM (Bureau International des Poids et Mesures)
Comments

SIR: Système International de Référence, International Reference System

APMP.RI(II)-K2.Co-58 results are linked to those of BIPM.RI(II)-K1.Co-58

BIPM.RI(II)-K1.Co-58 and APMP.RI(II)-K2.Co-58 results were published on 04 March 2003.

SIR equivalent activity of the radionuclide 58Co

Pilot institute BIPM
Bureau International des Poids et Mesures
BIPM - International Organization
Contact person Carine Michotte

+33 (0) 1 45 07 70 85
First Name Last Name
wwww@ww.www +356719836 Institute 1 Institute 1 Khmelnitskiy
Pilot laboratory
BIPM

Bureau International des Poids et Mesures, BIPM - International Organization, N/A

BNM-LNHB

Bureau National de Métrologie - Laboratoire National Henri Becquerel, France, EURAMET

CMI-IIR

Czech Metrology Institute - Inspectorate for Ionizing Radiation, Czechia, EURAMET

NMIJ AIST

National Metrology Institute of Japan, Japan, APMP

NPL

National Physical Laboratory, United Kingdom, EURAMET

OMH

Országos Mérésügyi Hivatal; Subsequently MKEH, now BKFH, Hungary, EURAMET

PTB

Physikalisch-Technische Bundesanstalt, Germany, EURAMET

Comparison
Comparison close
Results

BIPM.RI(II)-K1.Co-58 and APMP.RI(II)-K2.Co-58

MEASURAND : Equivalent activity of 58Co

  • Key comparison BIPM.RI(II)-K1.Co-58

Key comparison reference value:
The SIR reference value for this radionuclide is xR = 16.250 MBq, with a standard uncertainty uR = 0.040 MBq.
xR is the mean of six of the ten SIR results, see section 4.1 of the Final Report.

The degree of equivalence of each laboratory with respect to the reference value is given by a pair of terms:
Di = (xi - xR) and Ui, its expanded uncertainty (k = 2), both expressed in MBq. With n the number of laboratories,  when each laboratory has contributed to the computation of xR, see Appendix 2 of the Final Report.

The degree of equivalence between two laboratories is given by a pair of terms:
Dij =(Di - Dj) = (xi - xjand Uij, its expanded uncertainty (k = 2), both expressed in MBq. The approximation Uij ~ 2(ui2 + uj2)1/2 is used in for the computation of the pair-wise degrees of equivalence.
  • Linking APMP.RI(II)-K2.Co-58 to BIPM.RI(II)-K1.Co-58

The value xi is the equivalent activity for laboratory i participant in APMP.RI(II)-K2.Co-58 having been normalized to the value of the NMIJ as the linking laboratory.

The degree of equivalence of laboratory i participant in APMP.RI(II)-K2.Co-58 with respect to the key comparison reference value is given by a pair of terms:
Di = (xi - xR) and Ui, its expanded uncertainty (k = 2), both expressed in MBq.
The approximation Ui = 2(ui2 + uR2)1/2 is used in the Matrix of equivalence as none of these laboratories contributed to the computation of the key comparison reference value xR.

The degree of equivalence between two laboratories i and j, one participant in BIPM.RI(II)-K1.Co-58 and one in APMP.RI(II)-K2.Co-58, or both participants in APMP.RI(II)-K2.Co-58, is given by a pair of terms expressed in MBq:
Dij = Di - Dj and Uij, its expanded uncertainty (k = 2), approximated by
Uij = 2(ui2 + uj2 - 2ful2)1/2 with l being the linking laboratory when each laboratory is from APMP and f is the correlation coefficient.


These statements make it possible to extend the BIPM.RI(II)-K1.Co-58 Matrix of equivalence to all participants in APMP.RI(II)-K2.Co-58.
Comparison
Comparison close
Results

BIPM.RI(II)-K1.Co-58 and APMP.RI(II)-K2.Co-58

MEASURAND : Equivalent activity of 58Co

  • Key comparison BIPM.RI(II)-K1.Co-58

xi : result of measurement carried out in the SIR for the sample submitted by laboratory i
ui : combined standard uncertainty of xi

 Lab i xi
/ kBq
ui
/ kBq
Date of
measurement
       
 CMI-IIR 16108 123 80-01-07
 OMH 16197 51 86-06-30
 NPL 16257 119 91-06-20
 BNM-LNHB 16393 25 92-04-21
 PTB 16266 51 95-05-09
 NMIJ 16281 69 00-03-14


  • Key comparison APMP.RI(II)-K2.Co-58

xi : result of measurement carried out by laboratory i converted to the equivalent activity through the NMIJ
ui : combined standard uncertainty of xi

 Lab i* xi
/ kBq
ui
/ kBq
Measurement
report date
       
 NMIJ 16281 69 00-04-24
 BARC  16544 166 00-07-21
 CNEA 16378 148 00-07-09
 INER 16342 139 00-06-26
 KRISS 16325 34 00-07-19
 LNMRI 16749 119 00-07-04
 NIM 16208 91 00-06-23

* not all laboratories were eligible to be linked to the corresponding BIPM key comparison (see Final Report)