IEC 60522-1:2020 pdf free.Medical electrical equipment – Diagnostic X-rays -Determination of quality equivalent filtration and permanent filtration.
lf the PERMANENT FILTRATION of the combination of materials could reliably be found by additionof the QUALITY EQUIVALENT FILTRATION of the individual FILTERs or of the appropriate(sub-)stack(s), then the method in Figure 3 may be applied for the individual FILTERs or(sub-)stack(s). The PERMANENT FILTRATION is then found by adding the QuALITY EQUIVALENTFILTRATIONS of the FILTERS and/or (sub-)stack(s).
The boundary conditions for this case are as follows:
The HIGH vOLTAGE is at least 50 kV, and none of the materials comprising the PERMANENTFILTRATION:
has an atomic number larger than 26,or
has an atomic number larger than 30, and the sum of the QUALITY EQUIVALENT FILTRATION ofall other materials building the PERMANENT FILTRATION with atomic number 26 or smaller isat least 0,5 mm Al.
NOTE Under these conditions the PERMANENTFILTRATION or the QuALITYEQUIVALENT FILTRATION of its constituentFILTERS hardly depend on the RADIATION QUALITY i.e. on HIGH vOLTAGE or TARGET ANGLE – so addition of QuALITY EQUIVALENT FILTRATION values is appropriate.
Usually,the QUALITY EQUIVALENT FILTRATION depends on the RADIATION QUALITY, hence itdepends also on TARGET ANGLE.
lf the FILTERING MATERIAL is combined with just one X-RAY TUBE ASSEMBLY, it is recommended toperform the determination with an X-RAY TUBE ASSEMBLY with a TARGET with the same TARGETANGLE.
lf it is not known with which X-RAY TUBE ASSEMBLY the FILTERING MATERIAL will be used, then itis recommended to apply an X-RAY TUBE ASSEMBLY with a representative TARGET ANGLE such,that the deviation of the QUALITYEQUIVALENT FILTRATION over the typical range OF TARGET ANGLESin practical applications is minimized. For mammographic applications,this representativeTARGET ANGLE is 10 ° or11 °; for applications above a HIGH vOLTAGE of 50 kV, this representativeTARGET ANGLE is 10 °,11 °, or 12.
lf required per lEC 60601-1-3:2008 or per another document,the reference X-RAYTUBEASSEMBLY used for the determination in Figure 4 is equipped with FILTRATION for the intendedRADIATION QUALITY;otherwise a reference X-RAY TUBE ASSEMBLY with minimal FILTRATION isapplied.The TARGET material is chosen in line with the application.IEC 60522-1 pdf download.