ISO 4037-2:2019 pdf free

ISO 4037-2:2019 pdf free.Radiological protection一X and gamma reference radiation for calibrating dosemeters and doserate meters and for determining their response as a function of photon energy
The calibration factor and the correction factors for the standard instrument refer to specific spectra.If the energy dependence of the response of the standard instrument cannot be neglected and if the spectral distribution of the radiation for which the dosimetry shall be performed differs significantly from that used for the calibration, a correction factor may have to be applied. This may be the case if the radiation series for the calibration of the standard instrument and the radiation series for which the dosimetry shall be performed are different. The aim shall be that the expanded overall uncertainty (k= 2) of the calibration factor used shall not exceed 5 %.
For the highest level of dissemination of the phantom related quantities, e.g., by National Metrology Institutes, spectrometry is required for X-ray qualities with generating potential of and below 60 kV and for high energy photon fields with energies above that of the S-Co reference field. The air kerma,Ka, shall be determined by a primary or at least directly traceable standard and spectrometry of the reference field shall be performed, e.g. according to Annex B, both at the point of test.
For secondary standard laboratories for the realization of the phantom related quantities and for matched reference radiation fields, recommended values of conversion coefficients can be used, which are given in ISO 4037-3. These coefficients are determined at an X-ray unit with a constant potential high voltage generator deemed to be representative of the reference radiations specified in ISO 4037-1.The phantom related operational quantities, here indicated by the symbol H, are then calculated as given by Formula (1).
The determination of the appropriate conversion coefficients is based on spectrometry. A suitable spectrometer is used to measure the spectrum of the radiation quality under consideration. From this spectrum, the exact conversion coefficient can be calculated and applied to the measured value of the air kerma, Ka, free-in-air. This calculation uses conversion coefficients pertaining to mono-energetic radiation given by both ICRP and ICRU[4] from air kerma free-in-air to the phantom related quantity under consideration. Such spectrometry and the calculation of the exact conversion coefficient shall,in principle, be performed for the X-ray unit used to produce the reference radiation fields and for any required measuring quantity. A possible method to avoid the complex spectrometry is the use of recommended conversion coefficients listed in ISO 4037-3 for matched reference radiation fields. This is described in Clause 6.ISO 4037-2 pdf free download.