C Kessler

Comparison of the standards for air kerma of the NIST and the BIPM for 60Co gamma radiation

An indirect comparison of the standards for air kerma of the Dutch Metrology Institute (VSL), The Netherlands, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co radiation beam of the BIPM in September 2005. The comparison result, based on the calibration coefficients for three transfer standards and expressed as a ratio of the VSL and the BIPM standards for air kerma, is 0.9985 with a combined standard uncertainty of 2.2 ? 10?3. The latest result agrees with the result of the previous comparison in 60Co ? rays, made in 1996 and updated for recent changes made to the standards to give a value of 0.9982(37). The degrees of equivalence between the VSL and the other participants in the key comparison BIPM.RI(I)-K1 have been calculated and the results are presented in the form of a matrix. A graphical presentation is also given. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Summary of the BIPM.RI(I)-K1 comparison for air kerma in 60Co gamma radiation

International comparisons of air kerma in 137Cs gamma radiation beams have been made at the Bureau International des Poids et Mesures (BIPM) since 1994. Twelve national metrology institutes have taken part, seven of which have repeated the comparison over the intervening years. The key comparison reference value (KCRV) is taken as the BIPM evaluation, each comparison result being the ratio of the national metrology institute (NMI) evaluation to that of the BIPM standard under the same reference conditions. The degrees of equivalence between each NMI and the KCRV and a graphical presentation are given using the most recent published result for eleven NMIs. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Key comparison BIPM.RI(I)-K2 of the air-kerma standards of the ENEA-INMRI, Italy and the BIPM in low-energy x-rays

A key comparison has been made between the air-kerma standards of the ENEA-INMRI, Italy and the BIPM in the low-energy x-ray range. The results show the standards to be in agreement at the level of the standard uncertainty for the comparison of 1.9 parts in 10 3 . No significant trend with radiation quality is observed. The results are analysed and presented in terms of degrees of equivalence, suitable for entry in the BIPM key comparison database.

Comparison of the standards for absorbed dose to water of the VSL and the BIPM for 60Co γ-rays

An indirect comparison of the standards for the quantity absorbed dose to water was carried out between the Van Swinden Laboratorium (VSL) and the Bureau International des Poids et Mesures (BIPM) in September 2005. The comparison was based on the calibration coefficients determined for three NE2611A type ionization chambers under reference conditions in the 60Co beams of both institutes. The comparison result, reported as a ratio of the VSL and the BIPM evaluations, is 0.9926 with a relative standard uncertainty of 4.9 ? 10?3. This result replaces the previous indirect comparison result obtained in 2000 for the ongoing BIPM.RI(I)-K4 comparison. The degrees of equivalence for the VSL standard and the nine other national metrology institutes in this comparison are presented in the form of a matrix, together with those of a linked regional comparison. The opportunity was also taken to undertake a pilot study using the VSL water calorimeter at the BIPM. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Comparison of the standards for absorbed dose to water of the NMIJ and the BIPM for60Co γ-ray beams

A comparison of the standards for absorbed dose to water of the National Metrology Institute of Japan (NMIJ) and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 60Co ?-ray reference beam of the BIPM in November to December 2009 under the auspices of the key comparison BIPM.RI(I)-K4. The comparison result, based on the calibration coefficients for two transfer standards and expressed as a ratio of the NMIJ and the BIPM standards for absorbed dose to water, is 0.9960(46). The degrees of equivalence between the NMIJ and the other participants in this comparison have been calculated and the results are given in the form of a matrix for the ten national metrology institutes (NMIs) that have participated. A graphical presentation is also given. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Comparison of the standards for absorbed dose to water of the VNIIFTRI, Russia and the BIPM in60Co γ rays

A new comparison of the standards for absorbed dose to water of the All-Russian Scientific Research Institute for Physical-Technical and Radiotechnical Measurements (VNIIFTRI), Russia and of the Bureau International des Poids et Mesures (BIPM) has been made in 60Co gamma radiation in 2009. The results show that the VNIIFTRI and the BIPM standards for absorbed dose to water are in agreement, yielding a mean ratio of 0.9976 for the calibration coefficients of the transfer chambers, the difference from unity being within the combined standard uncertainty (0.0043) for this result. This result is consistent with the earlier 2001 comparison result of 0.9967 (43). The updated degrees of equivalence for the VNIIFTRI are compared with those of the other national metrology institutes as presented in the BIPM key comparison database. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Key comparison BIPM.RI(I)-K7 of the air-kerma standards of the NIST, USA and the BIPM in mammography x-rays.

A first key comparison has been made between the air-kerma standards of the PTB and the BIPM in mammography x-ray beams. The results show the standards to be in agreement at the level of the combined standard uncertainty of 3.7 parts in 103. A comparison of the standards has also been made in simulated mammography x-ray beams. The standards agree at the level of the combined standard uncertainty of 3.5 parts in 103. The results are analysed and presented in terms of degrees of equivalence for entry in the BIPM key comparison database. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).

Comparison of the standards for air kerma of the ITN (Portugal) and the BIPM for 137Cs γ-rays

A first comparison of the standards for air kerma of the Instituto Tecnologico e Nuclear (ITN), Portugal and of the Bureau International des Poids et Mesures (BIPM) has been carried out in 60 Co radiation under the auspices of the key comparison BIPM.RI(I)-K1. The comparison result, expressed as a ratio of the ITN standard and the BIPM standard, is 1.0015 (0.0018). The degrees of equivalence between the ITN and the other participants in the key comparison have been calculated and the results are presented in the form of a matrix. A graphical presentation is also given.

Comparison BIPM.RI(I)-K8 of high dose-rate Ir-192 brachytherapy standards for reference air kerma rate of the VSL and the BIPM

An indirect comparison of the standards for reference air kerma rate (RAKR) for 192Ir high dose rate (HDR) brachytherapy sources of the Physikalisch-Technische Bundesanstalt (PTB), Germany, and of the Bureau International des Poids et Mesures (BIPM) was carried out at the PTB in September 2011. The comparison result, based on the calibration coefficients for a transfer standard and expressed as a ratio of the PTB and the BIPM standards for reference air kerma rate, is 1.0003 with a combined standard uncertainty of 0.0099. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

Comparison of the standards for air kerma of the KRISS and the BIPM for 137Cs gamma radiation

A direct comparison of the standards for air kerma of the Korea Research Institute of Standards and Science (KRISS), Korea, and of the Bureau International des Poids et Mesures (BIPM) was carried out in the 137Cs radiation beam of the BIPM in August 2010. The result, expressed as a ratio of the KRISS and the BIPM standards for air kerma, is 0.9986 with a combined standard uncertainty of 2.2 ? 10?3. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCRI Section I, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).