MEASURAND : 24.5 keV neutron fluence
Degrees of equivalence Di and expanded uncertainty Ui (k = 2),
expressed in cm2/cm2
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MEASURAND : 24.5 keV neutron fluence
| Lab i | Di | Ui |
| / (cm2/cm2) | / (cm2/cm2) | |
| VNIIM | -0.012 | 0.026 |
| CIAE | -0.002 | 0.080 |
| NIST | -0.184 | 0.324 |
| PTB | 0.029 | 0.084 |
| NPL | 0.024 | 0.091 |
Results are presented under A4 printable format in Summary Results (.PDF file).
| Metrology area, Sub-field | Ionizing Radiation, Section III (Neutron Measurements) |
| Description | Comparison of neutron fluence |
| Time of measurements | 1993 - 1998 |
| Status | Approved for equivalence |
| Final Reports of the comparisons | |
| Measurand | Neutron fluence |
| Parameters | Neutron energy: 24.5 keV |
| Transfer device | Three Bonner spheres (2.5", 3.5" and 9.5") |
| Comparison type | Key Comparison |
| Consultative Committee | CCRI (Consultative Committee for Ionizing Radiation) |
| Conducted by | CCRI (Consultative Committee for Ionizing Radiation) |
| Comments | Four different fluence production techniques were used. Results published on 19 April 2010 Comparison of neutron fluence |
| Pilot institute |
NPL
National Physical Laboratory United Kingdom |
| Contact person | David THOMAS +44 (0) 20 8943 6853 |
| Pilot laboratory | |
|---|---|
| NPL |
National Physical Laboratory, United Kingdom, EURAMET |
| CIAE |
China Institute of Atomic Energy, China, APMP |
| NIST |
National Institute of Standards and Technology, United States, SIM |
| PTB |
Physikalisch-Technische Bundesanstalt, Germany, EURAMET |
| VNIIM |
D.I. Mendeleyev Institute for Metrology, Rosstandart, Russian Federation, COOMET |
This page proposes print-out on A4 paper (portrait) of the comparison details (best printed out using a black and white printer).
Please, select items to be printed out, then click on "OK" :
MEASURAND : 24.5 keV neutron fluence
|
The key comparison reference value, xR, is taken as 1. |
| The degree of equivalence of each laboratory i 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 cm2/cm2. Ui = 2ui. |
| The degree of equivalence between two laboratories i and j is given by a pair of terms: Dij = Di - Dj and Uij, its expanded uncertainty (k = 2), both expressed in cm2/cm2. In evaluating Uij = 2uij for the matrix of equivalence, account is taken of correlations between ui and uj (see CCRI(III)-K1 Final Report). |
MEASURAND : 24.5 keV neutron fluence
xi : measurement result obtained by laboratory i expressed as the mean ratio of measured instrument response by laboratory i to the reference instrument response
ui : combined standard uncertainty of xi
Measurements were performed between March 1993 and March 1998
|
Lab i |
xi |
ui |
| VNIIM | 0.988 | 0.013 |
| CIAE | 0.998 | 0.040 |
| NIST | 0.816 | 0.162 |
| PTB | 1.029 | 0.042 |
| NPL | 1.024 | 0.046 |
