CIPM MRA COMPARISON REPORTS
APMP.RI(I)-K7
Measurement of air kerma in mammography beams
Published on 20/02/2026 - © 2026 S. Guo et al
Citation S. Guo et al 2026 CIPM MRA Comparison reports
Authors
Siming Guo National Institute of Metrology (NIM) China 
Jinjie Wu National Institute of Metrology (NIM) China
Takahiro Tanaka National Metrology Institute of Japan (NMIJ AIST) Japan
Tseng-Te Huang Institute of Nuclear Energy Research (NRSL/INER) Chinese Taipei
Sibusiso Jozela National Metrology Institute of South Africa (NMISA) South Africa
Zakithi Msimang International Atomic Energy Agency (IAEA) IAEA - International Organization
Joao Cardoso International Atomic Energy Agency (IAEA) IAEA - International Organization
Abstract
The APMP/TCRI Dosimetry Working Group initiated the APMP.RI(I)-K7 key comparison of
the air kerma standards for mammography X-rays, measurements took place between 2020 and 2023. In total, five institutes took part in the comparison. Two ionization chambers were used as transfer standards circulated among the participants. The results showed that the
maximum difference between the participants and the Bureau International des Poids et Mesures (BIPM), evaluated using the comparison data of the linking laboratories of the National Institute of Metrology of China (NIM) and the National Metrology Institute of Japan (NMIJ), was less than 14.8 parts in 103 within the expanded uncertainty. This comparison supports the equivalence of the calibration capabilities of the participating laboratories.
the air kerma standards for mammography X-rays, measurements took place between 2020 and 2023. In total, five institutes took part in the comparison. Two ionization chambers were used as transfer standards circulated among the participants. The results showed that the
maximum difference between the participants and the Bureau International des Poids et Mesures (BIPM), evaluated using the comparison data of the linking laboratories of the National Institute of Metrology of China (NIM) and the National Metrology Institute of Japan (NMIJ), was less than 14.8 parts in 103 within the expanded uncertainty. This comparison supports the equivalence of the calibration capabilities of the participating laboratories.