IEC 60522-1:2020 pdf free download – Medical electrical equipment -Diagnostic X-rays
Steps for determining the QUALITY EQUIVALENT FILTRATION:
4a Place the FILTERING MATERIAL(S)(F3) to be measured in the X-RAY BEAM.Measure the AIR KERMA RATE at a HIGH vOLTAGE under the conditions stated in 4.2,using a suitableRADIATION DETECTOR(D) as described in 4.3.
4b Using an iterative measurement process, determine the HALF-VALUE LAYER referenced to aluminium of the X-RAY BEAM by adding aluminium reference FILTERs (R) into the beamuntil the AIR KERMA RATE is one-half of the value determined in step 4a.
4c While maintaining the reference FILTERs (R) determined from step 4b in the beam,remove the FILTERING MATERIAL(S)(F3) and replace it with aluminium FILTER(Al) andmeasure the resulting AIR KERMA RATE K2. Using an iterative measurement process,adjust the total thickness of the FILTER(Al) such that in step 4d the AlR KERMA RATE isdoubled.The resulting thickness of the FILTER(Al) represents the QuALITY EQUIVALENTFILTRATION of the FILTERING MATERIAL(S)(F3) under test (indicated by the dashed arrowin Figure 4).
4d Remove reference FILTERs(R) and compare the AlR KERMARATE to the value determined in step 4c.The value at 4d shall be twice as large.
4.7 X-ray simulations
A software tool may be used to simulate the RADIATION QUALITY and to determine the QuALITYEQUIVALENT FILTRATION. If the method of simulation has been validated against the methoddescribed in this document over the full range of use, including consideration of K-edge issues,also a simulation can be used as base for a statement of compliance.The validated computedvalue of the QuALITY EQUIVALENT FILTRATION shall not be larger than the MEASURED VALUE.Onrequest, the documentation of the method of validation and the results achieved shall be madeavailable to usERs of the product documentation which includes the corresponding statementof compliance. It shall be stated that a computed value is provided.
4.8 Compliance test
Compliance with a stated value of PERMANENT FILTRATION or with a stated value of the QuALITYEQUIVALENT FILTRATION of a FILTERING MATERIAL is achieved if the MEASURED VALUE determinedin the above tests is not less than the stated value and does not exceed the stated value bymore than 30 %.
5.1 Presentation of QuALITY EQUIVALENT FILTRATION values
The value of the QuALITY EQUIVALENT FILTRATION shall be expressed as the thickness inmillimetres of the reference material aluminium, described by its chemical symbol.
QUALITY EQUIVALENT FILTRATION values should be presented with a maximum of one decimalplace accuracy and a maximum of two significant figures.
NOTE 1 The indicated accuracy is in line with the limited accuracy of QuALITYEQUIVALENTFILTRATION determinations;see lEC TR 60522-2[2].
NOTE 2 The symbol for the marking is lEC 60417-5381:2002-10[1].
NOTE 3 IEC 60522-1 does not include the case of stating actual FILTERING MATERIAL(e.g. berylium). SeeIEC 60601-2-28[3] or IEC 60601-1-3 for requirements.
In case the materials building the PERMANENTFILTRATION have non-uniform thickness and/or arenon-perpendicular to the REFERENCE AXIs the location and orientation of determination of thePERMANENT FILTRATION shall be indicated.