Local Dosimeter for Measuring the Ambient Equivalent Dose of Photon Radiation, and Reading Method

An area dosimeter (1) for measuring the ambient equivalent dose (H*(10)) of photon radiation (P) including:

• a diffuser (30) for the photon radiation (P),
• a detector card (2) with at least one first pair (10) of photon radiation sensitive detection elements (12, 14) having identical response characteristics for the photon radiation to be measured (P),
• whereby the detector card (2) defines a card surface (E), and the two detection elements (12, 14) are arranged next to or above each other on the card surface (E) of the detector card (2), and whereby the arrangement of the diffuser (30) and the detection elements (12, 14) is constructed such that it is basically mirror symmetric to the card surface (E), such that the two detection elements (12, 14) for photon radiation are sensitive in the same manner from both sides of the card surface (E), in order that a measurement of the photon radiation (P) may be obtained in a range of almost 360°,
• whereby the first (12) of the two detection elements is positioned between two filters (52a, 52b) such that the photon radiation (P) arriving at the first detection element (12) is filtered either from the one (52a) filter or the other (52b) filter, depending on whether the photon radiation (P) arrives at the first detection element (12) from the front or the back, whereby the two filters (52a, 52b) are identical in respect to their spectral filtering effect, in order that the same spectral filtering effect be obtained from the front and from the back,
• whereby the second of the two detection elements (14) is not placed between such filters (52a, 52b) as is the case with the first detection element (12), in order that the photon radiation (P) arriving at the second detection element (14) displays a different spectral distribution than the spectrally filtered photon radiation (P) arriving at the first detection element (12).