The KCDB - the BIPM key comparison database – supports the CIPM MRA. The KCDB contains information on the internationally recognized Calibration and Measurement Capabilities (CMCs) for services available from the participating institutes, and the key and supplementary comparisons supporting these CMCs.

All data listed in the KCDB have been reviewed and approved within the CIPM Mutual Recognition Arrangement
BIPM.RI(II)-K1.Np-237 and EUROMET.RI(II)-K2.Np-237

**MEASURAND : Equivalent activity of ^{237}Np**

**Degrees of equivalence D_{i} and expanded uncertainty U_{i} (k = 2) expressed in MBq**

**Red diamonds **: participants in BIPM.RI(II)-K1.Np-237**Green triangles **: participants in EUROMET.RI(II)-K2.Np-237

__Note__: the right-hand axis shows approximate relative values only.

BIPM.RI(II)-K1.Np-237 and EUROMET.RI(II)-K2.Np-237

**MEASURAND : Equivalent activity of ^{237}Np**

Lab i | D_{i} | U_{i} |

/ MBq | / MBq | |

BIPM | 0.6 | 1.6 |

PTB | -0.1 | 0.3 |

IRMM | 0.1 | 0.3 |

LNE-LNHB | 0.4 | 0.5 |

CIEMAT | 0.7 | 0.8 |

NPL | -0.6 | 0.9 |

NRC | -0.8 | 1.7 |

In **green**: participants in EUROMET.RI(II)-K2.Np-237

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

EUROMET.RI(II)-K2.Np-237

Metrology area, Sub-field | Ionizing Radiation, Section II (Measurement of Radionuclides) |

Description | Activity of radionuclide Np-237 |

Time of measurements | 1997 - 2001 |

Status | Approved for equivalence |

Final Reports of the comparisons | |

Measurand | Activity |

Comparison type | Key Comparison |

Consultative Committee | CCRI (Consultative Committee for Ionizing Radiation) |

Conducted by | EURAMET (European Association of National Metrology Institutes) |

RMO Internal Identifier | EUROMET Project No 416 |

Comments |
SIR equivalent activity of the radionuclide |

Pilot institute |
NPL
National Physical Laboratory United Kingdom |

Contact person | M.J. Woods +44 (0) 20 8943 6425 |

Pilot laboratory | |
---|---|

NPL |
National Physical Laboratory, United Kingdom, EURAMET |

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

CIEMAT |
Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas, Spain, EURAMET |

NRC |
National Research Council, Canada, SIM |

PTB |
Physikalisch-Technische Bundesanstalt, Germany, EURAMET |

This page proposes print-out on A4 paper (portrait) of the comparison details (best printed out using a black and white printer).

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Results:

BIPM.RI(II)-K1.Np-237 and EUROMET.RI(II)-K2.Np-237

**MEASURAND : Equivalent activity of ^{237}Np**

- Key comparison BIPM.RI(II)-K1.Np-237

Key comparison reference value: the SIR reference value for this radionuclide is (see section 4.1 of the Final Report).u_{R} = 0.11 MBq |

The degree of equivalence of each laboratory with respect to the reference value is given by a pair of terms: and D = (_{i}x- _{i} x_{R}), its expanded uncertainty (U_{i}k = 2), both expressed in MBq. With n the number of laboratories, when each laboratory has contributed to the computation of .x_{R} |

The degree of equivalence between two laboratories is given by a pair of terms:and D =(_{ij}D - _{i}D) = (_{j}x - _{i}x) _{j}, its expanded uncertainty (U_{ij}k = 2), both expressed in MBq. The approximation U_{ij}~ 2( is used in the Matrix of equivalence. u_{i}^{2} + u_{j}^{2})^{1/2} |

- Linking EUROMET.RI(II)-K2.Np-237 to BIPM.RI(II)-K1.Np-237

The value i participant in EUROMET.RI(II)-K2.Np-237 having been normalized using the SIR measurements of the BIPM, PTB, and the IRMM as linking laboratories. |

The degree of equivalence of laboratory i participant in EUROMET.RI(II)-K2.Np-237 with respect to the key comparison reference value is given by a pair of terms: and D = (_{i}x_{i} - x_{R}), its expanded uncertainty (U_{i}k = 2), both expressed in MBq.The approximation is used in the Matrix of equivalence.U = 2(_{i}u_{i}^{2} + u_{R}^{2})^{1/2} |

The degree of equivalence between two laboratories i and j, one participant in BIPM.RI(II)-K1.Np-237 and one in EUROMET.RI(II)-K2.Np-237, or both participants in EUROMET.RI(II)-K2.Np-237, is given by a pair of terms expressed in MBq: and D = _{ij}D - _{i}D_{j}, its expanded uncertainty (U_{ij}k = 2), approximated by with U = 2(_{ij}u_{i}^{2} + u_{j}^{2} - 2fu_{l}^{2})^{1/2} being the standard uncertainty of the link when each laboratory is from EUROMET and u_{l} is the correlation coefficient. f |

These statements make it possible to extend the BIPM.RI(II)-K1.Np-237 matrix of equivalence to all participants in EUROMET.RI(II)-K2.Np-237. |

BIPM.RI(II)-K1.Np-237 and EUROMET.RI(II)-K2.Np-237

**MEASURAND : Equivalent activity of ^{237}Np**

- Key comparison BIPM.RI(II)-K1.Np-237

**x**_{i} : result of measurement carried out in the SIR for the sample submitted by laboratory *i*

Lab i |
x _{i}/ kBq |
u _{i}/ kBq |
Date of measurement |

BIPM |
75440 | 790 | 12-06-1998 |

PTB |
74740 | 220 | 02-02-2006 |

IRMM |
74950 | 180 | 27-02-2007 |

- Key comparison EUROMET.RI(II)-K2.Np-237

**x**_{i} : result of measurement carried out at laboratory *i* converted to the equivalent activity through the linking laboratories BIPM, PTB and the IRMM**u**_{i} : combined standard uncertainty of **x**_{i}

** Lab i**

/ kBq

/ kBq