[en] Wide agreement has been achieved among the main Bodies and Organisations involved in standardisation of radiation protection, related to the operational quantities for personal dosimetry. Since their definition in 1985, several reports have been published to clarify and define the experimental set up to be used for the calibration of dosemeters in terms of the above-mentioned quantities. Among these lines, ICRU 47 has listed five different phantoms that are used for calibration and whose results were accurate, within accepted uncertainties. However, to achieve uniformity in calibration procedures, the 30 cm x 30 cm x 15 cm PMMA slab phantom was recommended. The secondary calibration Laboratory from the Institut de Techniques Energetiques at the Technical University of Catalonia (UPC) agreed with the Spanish Nacional Laboratory to adopt the recommended PMMA phantom but to improve the accuracy of the calibration procedure, by introducing a correction factor for backscatter differences in a PMMA and an ICRU slab phantom. Such corrections were of the order of 8% for the low-energy X-ray qualities. Recently, ISO in ISO 4037-3, has proposed the ISO water slab phantom which consists of a 30 cm x 30 cm x 15 cm water phantom with PMMA walls (front wall 2.5 mm thick). This new phantom could be substituted by the above mentioned PMMA phantom for radiation qualities with mean energy equal or above that of ¹³⁷Cs. The aim of this work is to compare the influence of both phantoms when calibrating personal dosemeters with photons. A set of four TL personal dosemeters that are used in the UPC personal dosimetry Service and an electronic personal dosemeter (SIEMENS EPD-2) were calibrated in terms of H_p(10) and H_p(0.07) using the two proposed phantoms. Calibration factors for ISO X-ray narrow spectra, ¹³⁷Cs and ⁶⁰Co were experimentally obtained for each phantom and compared. In the TL measurements, differences were found to be within TL statistical uncertainty, provided that a backscattering correction factor was used, whereas in the calibration of the electronic device, the response of the dosemeter was the same, irrespective of the calibration phantom used. For such system the backscattering correction factor should not be used. These results show that the adoption of the new ISO phantom, it will not introduce any significant change in former photon calibration in the range (33 keV - 1250 keV). It has the advantage of being a better substitute of the ICRU slab phantom and therefore of not needing any correction for backscattering differences. However, due to the greater case of manufacture and use, the PMMA slab phantom can still be used, mainly, for routine dosemeter calibrations. (author)