IEC 60580 pdf download.Medical electrical equipment – Dose area product meters
1 Scope and object
This International Standard specifies the performance and testing of DOSE AREA PRODUCT METERS with IONIZATION CHAMBERS intended to measure DOSE AREA PRODUCT and/or DOSE AREA PRODUCT RATE to which the PATIENT is exposed during MEDICAL RADIOLOGICAL EXAMINATIONS . The object of this International Standard is 1 ) to establish requirements for a satisfactory level of performance for DOSE AREA PRODUCT METERS , and 2) to standardize the methods for the determination of compliance with this level of performance.
3.9 DOSE AREA PRODUCT RATE (Letter symbol K & ·A ) quotient of an increment of DOSE AREA PRODUCT by the corresponding increment of time. The unit of DOSE AREA PRODUCT RATE is Gym 2 /s 3.10 EFFECTIVE RANGE (of INDICATED VALUES ) range of INDICATED VALUES for which an instrument complies with a stated performance; the maximum (minimum) EFFECTIVE INDICATED VALUE is the highest (lowest) in this range The concept of EFFECTIVE RANGE may, for example, also be applied to scale readings and to related quantities that are not directly indicated by the instrument, e.g. input current (IEC 60731 ) NOTE The EFFECTIVE RANGE of INDICATED VALUES is referred to as EFFECTIVE RANGE in this standard. 3.1 1 EXPANDED UNCERTAINTY quantity defining the interval about the result of a measurement within which the values that could reasonably be attributed to the measurand may be expected to lie with a higher degree of confidence (IEC 60731 ) 3.1 2 FILTRATION modification of characteristics of ionizing radiation on passing through matter NOTE FILTRATION includes: – modification of the energy spectrum of ionizing radiation by preferential absorption of components; – modification of the spatial distribution of radiation intensity over the cross section of a radiation beam, by differential ATTENUATION . 3.1 3 HALF – VALUE LAYER thickness of a specified material which under NARROW BEAM CONDITIONS attenuates photon radiation according to its energy spectrum to an extent such that the AIR KERMA RATE is reduced to one half of the value that is measured without the material 3.14 INDICATED VALUE value of a quantity derived from the scale reading of an instrument together with any scale factors indicated on the control panel of the instrument (IEC 60731 ) 3.1 5 INFLUENCE QUANTITY any external quantity that may affect the performance of an instrument (e.g. ambient temperature, RADIATION QUALITY etc.) (IEC 60731 )
3.1 6 INSTRUMENT PARAMETER any internal property of an instrument that may affect the performance of this instrument (IEC 60731 ) 3.1 7 INTRINSIC ERROR deviation of the MEASURED VALUE (i.e. the INDICATED VALUE , corrected to REFERENCE CONDITIONS ) from the CONVENTIONAL TRUE VALUE under STANDARD TEST CONDITIONS (IEC 60731 ) 3.18 IONIZATION CHAMBER detector consisting of a chamber filled with a suitable medium, usually gaseous, in which an electric field, insufficient to induce charge multiplication, is provided for the collection at the electrodes of charges associated with ions and the electrons produced in the SENSITIVE VOLUME of the detector by ionizing radiation NOTE For use with DOSE AREA PRODUCT METERS , IONIZATION CHAMBERS are constructed in such a way as to allow the air inside the measuring volume to communicate freely with the atmosphere. Sealed chambers are not suitable for use with DOSE AREA PRODUCT METERS , because the necessary wall thickness of a sealed chamber may cause an unacceptable energy dependence of the RESPONSE and because the long term stability of sealed chambers is not guaranteed. 3.1 9 IRRADIATION TIME duration of irradiation determined according to specific methods, usually the time during which the rate of a RADIATION quantity exceeds a specified level 3.20 LEAKAGE CURRENT any current in the signal path arising in the detector and/or MEASURING ASSEMBLY which is not produced by ionization in the IONIZATION CHAMBER 3.21 LIMITS OF VARIATION maximum VARIATION of a PERFORMANCE CHARACTERISTIC , y, permitted by this standard. If LIMITS OF VARIATION are stated as ±L %, the VARIATION , ∆y/y, expressed as a percentage, shall remain in the range from –L % to +L % (IEC 60731 )