Technical protocol for calibration of ambient dose equivalent (rate) meters in ISO neutron reference fields

Nuclear plants and the area of industry that works with resources based on neutron irradiation fields require monitoring of the ambient dose equivalent (rate) for neutrons, especially within the context of radiological protection. Challenges related to the broad spectrum of energy distribution of neutron fields still require a more careful interpretation when using this equipment, making their traceability in these different spectra essential for a correct reading. The response or calibration factor of an instrument is a unique property of the instrument type, and may depend on the ambient dose equivalent ratio, the spectrum of the neutron source, or the angle of incidence of neutrons; but is not recommended to be a function of the characteristics of the calibration setup or the experimental techniques employed. Therefore, it is essential to ensure that the calibration is independent of the technique and factors such as the distance from the source to the device and the size of the calibration room. (author)