ISO 4037:2019 Validation of radiation qualities by means of half-value layer and H_p(10) dosimetry

Radiation qualities were characterised and validated at the fully automated X-ray calibration facility of the Individual Monitoring Service at Helmholtz Zentrum Muenchen by using half-value layer and H_p(10) dosimetry approaches specified in the updated ISO 4037:2019 standard. As the ISO 4037 contains a somewhat vague description of the half-value layer procedure, we extended it to be more constrained and thus less subjective in its implementation. We specify both the measurement and data analysis steps performed in order to provide reproducible half-value layer results and compare the results with the H_p(10) dosimetry-based validation approach specified in the ISO 4037 as an alternative for field validation. Finally, we discuss the implications of our results and the extended procedure on validation and the recent changes to the ISO 4037. (authors)