IEC 62467-1 pdf download – Medical electrical equipment – Dosimetric instruments as used in brachytherapy – Part 1: Instruments based on well-type ionization chambers

IEC 62467-1 pdf download – Medical electrical equipment – Dosimetric instruments as used in brachytherapy – Part 1: Instruments based on well-type ionization chambers
1Scope and object
This part of IEC 62467 specifies the performance and some related constructionalrequirements of wELL-TYPE IONIZATION CHAMBERs and associated measurement apparatus,asdefined in Clause 3, intended for the determination of a quantity, such as AlR KERMA STRENGTHor REFERENCE AIR KERMA RATE in photon radiation fields or ABSORBED DOSE TO WATER at adepth,in photon and beta radiation fields used in BRACHYTHERAPY，after appropriatecalibration for a given type of source.
This International Standard covers the techniques for the quantification of the quantityappropriate for the BRACHYTHERAPY source under consideration. This quantity may be AIRKERMA STRENGTH or REFERENCE AIR KERMA RATE at 1 m , or ABSORBED DosE To wATER at a depth(e.g.2 mm or 5 mm). Measurement of these quantities may be accomplished by a variety ofWELL-TYPE IONIZATION CHAMBERS or systems currently available for this purpose. This standardapplies to products intended for low dose rate, high dose rate, intravascular, both photon andbeta，BRACHYTHERAPY measurements. lt does not apply to instruments for nuclear medicineapplications. The application of the standard is limited to instruments that incorporate wELL-TYPE IONIZATION CHAMBERs as detectors.
The intended use is the measurement of the output of radioactive,encapsulated sources forintracavitary (insertion into body cavities) or interstitial (insertion’ into body tissue)applications.
The object of this standard is
a) to establish requirements for a satisfactory level of performance for wELL-TYPE CHAMBER
sYSTEMs,and
b) to standardize the methods for the determination of compliance with this level of
performance.
This standard is not concerned with the safety aspects of wELL-TYPE CHAMBER SYSTEMs.TheWELL-TYPE CHAMBER SYSTEMs covered by this standard are not intended for use in patientenvironment.The electrical safety of wELL-TYPE CHAMBER SYSTEMS is covered in lEC 61010-1.The operation of the electrometer measuring system is covered in lEC 60731.
2Normative references
The following referenced documents are indispensable for the application of this document.For dated references, only the edition cited applies. For undated references, the latest editionof the referenced document (including any amendments) applies.
IEC 60050-393:2003,International Electrotechnical Vocabulary – Part 393: Nuclearinstrumentation – Physical phenomena and basic concepts
IEC60417,Graphical symbols for use on equipment
IEC 60580:2003,Medical electrical equipment – Dose area product meters
IEC 60601-1:2005，Medical electrical equipment – Part 1: General requirements for basicsafefy and essenfial performance
IEC 60731:1997, Medical electrical equipment – Dosimeters with ionization chambers as usedin radiotherapy
IEC/TR 60788;2004,Medical electrical equipment – Glossary of defined terms
IEC 61187,Electrical and electronic measuring equipment – Documentation
IEC 61674:1997,Medical electrical equipment – Dosimeters with ionization chambers and/orsemi-conductor detectors as used in X-ray diagnostic imaging
ISO/IEC Guide 99,International vocabulary of metrology – Basic and general concepts andassociated ferms (vIM)
Terms and definitions
For the purposes of this document the following definitions apply.
The definitions given in this standard are generally in agreement with those in lEC/TR 60788and ISOIEC Guide 99 (IVM). Any term not defined in this clause or in the relevantpublications cited in the lndex of defined terms has the meaning defined in lEC/TR 60788 andisO/IEC Guide 99 or is assumed to be in general scientific usage.
3.1
absorbed dose to waterp
quotient of dE by dm where dE is the mean energy imparted by IONIZING RADIATION to water ofmass dw
NOTE 1 The unit of AB5ORBED DosE To wATER is Gy (where 1 Gy = 1 J·kgy”.
NOTE 2 This definition is derived from the definition in C.4 of lCRU 33 (see Bibliography).[IEC 60731:1997, definition 3.26]
3.2
air kerma strength
product of AIR KERMA RATE in free space (in vacuo) due to photons greater than a low energycut off and the square of the distance of the calibration point from the source centre along theperpendicular bisector
NOTE 1 Energy cut-off is generally 5 kev.NOTE 2 The unit is Gy m”is.
NOTE 3 ln practice the unit pGy m2h is used frequently.3.3
chamber assembly leakage currentleakage current
any current in the signal path arising in the CHAMBER ASSEMBLY which is not produced byionization in the measuring volume
NOTE lt is distinguished from zERo DRIFT or ZERo SHIFT which arises in the MEASURING ASSEMBLY.