E61.01 - Dosimetry

SIGNIFICANCE AND USE
4.1 Standards such as ISO 11137-1 (radiation sterilization of health care products) and ISO 14470 (irradiation of food) contain requirements that dosimetry used in the development, validation, and routine control of the process shall have measurement traceability to national or international standards and shall have a known level of uncertainty. The magnitude of the measurement uncertainty is important for assessing the results of the measurement system.  
4.1.1 This guide provides information on how to meet the fundamental requirement to determine a known level of uncertainty associated with a dose measurement, how to calculate the overall uncertainty, and how the uncertainty may differ depending on the application (e.g., OQ and PQ dose measurements, routine dose measurement, determination of minimum absorbed dose (Dmin) or maximum absorbed dose (Dmax) from the monitoring location dose (Dmon)). Information is provided on how to identify and calculate different components of uncertainty used to establish an uncertainty budget.  
4.2 Information on the range of achievable uncertainty values for specific dosimetry systems is given in the ISO/ASTM standards for the specific dosimetry systems. While the uncertainty values given in specific dosimetry standards are achievable, it should be noted that both smaller and larger uncertainty values might be obtained depending on measurement conditions and instrumentation. For more information, see also ISO/ASTM 52628.  
4.3 This guide uses the methodology adopted by the GUM for estimating uncertainties in measurements (see 2.4). Therefore, components of uncertainty are evaluated as either Type A uncertainty or Type B uncertainty.  
4.3.1 Quantifying individual components of uncertainty may assist the user in identifying actions to reduce the combined measurement uncertainty.  
4.4 Although this guide provides a framework for assessing uncertainty, it cannot substitute for critical thinking, intellectual honesty, and experi...
SCOPE
1.1 This standard provides guidance on the use of concepts described in the JCGM (Joint Committee for Guides in Metrology) Evaluation of Measurement Data – Guide to the Expression of Uncertainty in Measurement (GUM) to estimate the uncertainties in the measurement of absorbed dose in radiation processing.  
1.2 Methods are given for identifying, evaluating, and estimating the components of measurement uncertainty associated with the use of dosimetry systems, and for calculating combined standard measurement uncertainty and expanded uncertainty of dose measurements based on the GUM methodology.  
1.3 Examples are given on how to develop a measurement uncertainty budget and a statement of uncertainty.  
1.3.1 Key components of uncertainty are derived as part of the derivation of the uncertainty budget. This standard identifies which components of uncertainty are carried forward as part of other analyses (e.g., assessment of process capability and process targets, and process variability), and which components from other standards are brought forward into this standard (e.g., precision of the dose measurement, calibration curve fit, and indirect measurement of dose).  
1.4 This document is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and provides guidance for achieving compliance with the requirements of ISO 11137-1 (radiation sterilization of health care products), ISO 14470 (treatment of food), and ISO/ASTM 52628 related to the evaluation and documentation of the uncertainties associated with measurements made with a dosimetry system. It is intended to be read in conjunction with ISO/ASTM 52628 (Standard Practice for Dosimetry in Radiation Processing), and ISO/ASTM 51261 (Practice for Calibration of Routine Dosimetry Systems for Radiation Processing).  
1.5 To achieve compliance with the requirements of ISO 11137-1 (radiation sterilization of hea...

SIGNIFICANCE AND USE
4.1 Ionizing radiation is used to produce various desired effects in products. Examples of applications include the sterilization of medical products, microbial reduction, modification of polymers and electronic devices, and curing of inks, coatings, and adhesives (4).  
4.2 Absorbed-dose measurements, with statistical controls and documentation, are necessary to ensure that products receive the desired absorbed dose. These controls include a program that addresses requirements for calibration of routine dosimetry system.  
4.3 A routine dosimetry system calibration procedure as described in this document provides the user with a dosimetry system whose dose measurements are traceable to national or international standards for the conditions of use (see Annex A4). The dosimetry system calibration is part of the user’s measurement management system.
SCOPE
1.1 This practice specifies the requirements for calibrating routine dosimetry systems for use in radiation processing, including establishing measurement traceability and estimating uncertainty in the measured dose using the calibrated dosimetry system.
Note 1: Regulations or other directives exist in many countries that govern certain radiation processing applications such as sterilization of healthcare products and radiation processing of food requiring that absorbed-dose measurements be traceable to national or international standards (ISO 11137-1, Refs (1-3)2).  
1.2 The absorbed-dose range covered is up to 1 MGy.  
1.3 The radiation types covered are photons and electrons with energies from 80 keV to 25 MeV.  
1.4 This document is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and describes a means of achieving compliance with the requirements of ASTM E2628 “Practice for Dosimetry in Radiation Processing” for the calibration of routine dosimetry systems. It is intended to be read in conjunction with ASTM E2628 and the relevant ASTM or ISO/ASTM standard practice for the dosimetry system being calibrated referenced in Section 2.  
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
4.1 Ionizing radiation produces physical or chemical changes in many materials that can be measured and related to absorbed dose. Materials with radiation-induced changes that have been thoroughly studied can be used as dosimeters in radiation processing.  
Note 3: The scientific basis for commonly used dosimetry systems and detailed descriptions of the radiation-induced interactions are given in ICRU Report 80.  
4.2 Before a material can be considered for use as a dosimeter, certain characteristics related to manufacture and measurement of its response to ionizing radiation need to be considered, including:  
4.2.1 the ability to manufacture batches of the material with evidence demonstrating a reproducible radiation-induced change,  
4.2.2 the availability of instrumentation for measuring this change, and  
4.2.3 the ability to take into account effects of influence quantities on the dosimeter response and on the measured absorbed-dose values.  
4.3 Dosimeter/dosimetry system characterization is conducted to determine the performance characteristics for a dosimeter/dosimetry system related to its capability for measuring absorbed dose. The information obtained from dosimeter/dosimetry system characterization includes the reproducibility of the measured absorbed-dose value, the useful absorbed-dose range, effects of influence quantities, and the conditions under which the dosimeters can be calibrated and used effectively.
Note 4: When dosimetry systems are calibrated under the conditions of use, effects of influence quantities may be minimized or eliminated, because the effects can be accounted for or incorporated into the calibration method (see ISO/ASTM Practice 51261).  
4.4 The influence quantities of importance might differ for different radiation processing applications and facilities. For references to standards describing different applications and facilities, see ISO/ASTM Practice 52628.  
4.5 Classification of a dosimeter as a type I dosimeter ...
SCOPE
1.1 This guide provides guidance on determining the performance characteristics of dosimeters and dosimetry systems used in radiation processing.  
1.2 This guide describes the influence quantities that might affect the performance of dosimeters and dosimetry systems and that should be considered during dosimeter/dosimetry system characterization.  
1.3 Users of this guide are directed to existing standards and literature for procedures to determine the effects from individual influence quantities and from combinations of more than one influence quantity.  
1.4 Guidance is provided regarding the roles of the manufacturers, suppliers, and users in the characterization of dosimeters and dosimetry systems.  
1.5 This guide does not address how the dosimeter/dosimetry system characterization information is to be used in radiation processing applications or in the calibration of dosimetry systems.
Note 1: For guidance on the use of dosimeter/dosimetry system characterization information for the selection and use of a dosimetry system, the user is directed to ISO/ASTM Practice 52628.
Note 2: For guidance on the use of dosimeter/dosimetry system characterization information for dosimetry system calibration, the user is directed to ISO/ASTM Practice 51261.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
4.1 Radiation processing of articles in both commercial and research applications may be carried out for a number of purposes. These include, for example, sterilization of health care products, reduction of the microbial populations in foods and modification of polymers. The radiations used may be accelerated electrons, gamma-radiation from radionuclide sources such as cobalt-60, or X-radiation.  
4.2 To demonstrate control of radiation processes that are dependent on the delivery of a known dose, the absorbed dose must be measured using a dosimetry system, the calibration of which, is traceable to appropriate national or international standards. The radiation-induced change in the dosimeter is evaluated and related to absorbed dose through calibration. Dose measurements required for particular processes are described in other standards referenced in this practice.
SCOPE
1.1 This practice describes the basic requirements that apply when making absorbed dose measurements in accordance with the ASTM E61 series of dosimetry standards. In addition, it provides guidance on the selection of dosimetry systems and directs the user to other standards that provide specific information on individual dosimetry systems, calibration methods, uncertainty estimation and radiation processing applications.  
1.2 This practice applies to dosimetry for radiation processing applications using electrons or photons (gamma- or X-radiation).  
1.3 This practice addresses the minimum requirements of a measurement management system, but does not include general quality system requirements.  
1.4 This practice does not address personnel dosimetry or medical dosimetry.  
1.5 This practice does not apply to primary standard dosimetry systems.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
3.1 The purpose of this standard is to facilitate communication and promote common understanding within the professionals in radiation processing research and industry.  
3.2 Unambiguous communication of concepts is crucial taking into account the relevant implications that may arise from misunderstandings with regard to equipment and materials involved in the standards dealing with any subject regarding radiation processing activities. Concepts dealing with dosimetry related to radiation processing and procedures for preparation, testing, and using dosimetry systems to determine the absorbed dose are present in all standards developed by E61 and ISO/TC85/WG3 and need to be designated by common terms and described by harmonized definitions in order to avoid misunderstandings.
SCOPE
1.1 This terminology standard lists terms and definitions related to radiation processing concepts, especially radiation dose measurements. Use of this standard, and the common terminology, will foster clearer communication, and remove ambiguity.  
1.2 The use of ionizing radiation for the treatment of commercial products such as the sterilization of medical devices, the reduction of microbial contamination in food or the modification of polymers is referred to as radiation processing. The types of radiation used may be gamma radiation (typically from cobalt-60 sources), X-radiation or accelerated electrons.  
1.3 This standard provides terms and definitions for dosimetry for radiation processing concepts dealing with procedures related to operational qualification, performance qualification, and routine processing that may influence absorbed dose in the products, and types of dosimetry systems that may be used during calibration or on a routine basis as part of quality assurance in commercial radiation processing of products.  
1.4 When selecting terms and definitions, special care has been taken to include the terms that need to be defined, that is to say, either because the definitions are essential to the correct understanding of the corresponding concepts or because some specific ambiguities need to be addressed.  
1.5 The “Discussion” appended to certain definitions offers clarification or examples to facilitate understanding of the concepts described. In certain cases, miscellaneous information is also included, for example, the units in which a quantity is normally measured, recommended parameter values, references, etc.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.  
1.7 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

SIGNIFICANCE AND USE
4.1 Radiation processing of articles in both commercial and research applications may be carried out for a number of purposes. These include, for example, sterilization of health care products, reduction of the microbial populations in foods and modification of polymers. The radiations used may be accelerated electrons, gamma-radiation from radionuclide sources such as cobalt-60, or X-radiation.  
4.2 To demonstrate control of radiation processes that are dependent on the delivery of a known dose, the absorbed dose must be measured using a dosimetry system, the calibration of which, is traceable to appropriate national or international standards. The radiation-induced change in the dosimeter is evaluated and related to absorbed dose through calibration. Dose measurements required for particular processes are described in other standards referenced in this practice.
SCOPE
1.1 This practice describes the basic requirements that apply when making absorbed dose measurements in accordance with the ASTM E61 series of dosimetry standards. In addition, it provides guidance on the selection of dosimetry systems and directs the user to other standards that provide specific information on individual dosimetry systems, calibration methods, uncertainty estimation and radiation processing applications.  
1.2 This practice applies to dosimetry for radiation processing applications using electrons or photons (gamma- or X-radiation).  
1.3 This practice addresses the minimum requirements of a measurement management system, but does not include general quality system requirements.  
1.4 This practice does not address personnel dosimetry or medical dosimetry.  
1.5 This practice does not apply to primary standard dosimetry systems.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
4.1 All measurements, including dose measurements, have an associated uncertainty. The magnitude of the measurement uncertainty is important for assessing the quality of the results of the measurement system.  
4.2 Information on the range of achievable uncertainty values for specific dosimetry systems is given in the ISO/ASTM standards for the specific dosimetry systems. While the uncertainty values given in specific dosimetry standards are achievable, it should be noted that both smaller and larger uncertainty values might be obtained depending on measurement conditions and instrumentation. For more information see also ISO/ASTM 52628.  
4.3 This guide uses the methodology adopted by the GUM for estimating uncertainties in measurements (see 2.4). Therefore, components of uncertainty are evaluated as either Type A uncertainty or Type B uncertainty.  
4.4 Quantifying individual components of uncertainty may assist the user in identifying actions to reduce the measurement uncertainty.  
4.5 Periodically, the uncertainty should be reassessed to confirm the existing estimate. Should changes occur that could influence the existing component estimates or result in the addition of new components of uncertainty, a new estimate of uncertainty should be established.  
4.6 Although this guide provides a framework for assessing uncertainty, it cannot substitute for critical thinking, intellectual honesty, and professional skill. The evaluation of uncertainty is neither a routine task nor a purely mathematical one; it depends on detailed knowledge of the nature of the measurand and of the measurement method and procedure used. The quality and utility of the uncertainty quoted for the result of a measurement therefore ultimately depends on the understanding, critical analysis, and integrity of those who contribute to the assignment of its value (JCGM 100:2008).
SCOPE
1.1 This standard provides guidance on the use of concepts described in the JCGM Evaluation of Measurement Data – Guide to the Expression of Uncertainty in Measurement (GUM) to estimate the uncertainties in the measurement of absorbed dose in radiation processing.  
1.2 Methods are given for identifying, evaluating and estimating the components of measurement uncertainty associated with the use of dosimetry systems and for calculating combined standard measurement uncertainty and expanded (overall) uncertainty of dose measurements based on the GUM methodology.  
1.3 Examples are given on how to develop a measurement uncertainty budget and a statement of uncertainty.  
1.4 This document is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and provides guidance for achieving compliance with the requirements of ISO/ASTM 52628 related to the evaluation and documentation of the uncertainties associated with measurements made with a dosimetry system. It is intended to be read in conjunction with ISO/ASTM 52628, ISO/ASTM 51261 and ISO/ASTM 52701.  
1.5 This guide does not address the establishment of process specifications or conformity assessment.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
4.1 Radiation processing of articles in both commercial and research applications may be carried out for a number of purposes. These include, for example, sterilization of health care products, reduction of the microbial populations in foods and modification of polymers. The radiations used may be accelerated electrons, gamma-radiation from radionuclide sources such as cobalt-60, or X-radiation.  
4.2 To demonstrate control of the radiation process, the absorbed dose must be measured using a dosimetry system, the calibration of which, is traceable to appropriate national or international standards. The radiation-induced change in the dosimeter is evaluated and related to absorbed dose through calibration. Dose measurements required for particular processes are described in other standards referenced in this practice.
SCOPE
1.1 This practice describes the basic requirements that apply when making absorbed dose measurements in accordance with the ASTM E61 series of dosimetry standards. In addition, it provides guidance on the selection of dosimetry systems and directs the user to other standards that provide specific information on individual dosimetry systems, calibration methods, uncertainty estimation and radiation processing applications.  
1.2 This practice applies to dosimetry for radiation processing applications using electrons or photons (gamma- or X-radiation).  
1.3 This practice addresses the minimum requirements of a measurement management system, but does not include general quality system requirements.  
1.4 This practice does not address personnel dosimetry or medical dosimetry.  
1.5 This practice does not apply to primary standard dosimetry systems.  
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
4.1 Ionizing radiation produces physical or chemical changes in many materials that can be measured and related to absorbed dose. Materials with radiation-induced changes that have been thoroughly studied can be used as dosimeters in radiation processing. Note 3—The scientific basis for commonly used dosimetry systems and detailed descriptions of the radiation-induced interactions are given in ICRU Report 80.  
4.2 Before a material can be considered for use as a dosimeter, certain characteristics related to manufacture and measurement of its response to ionizing radiation need to be considered, including:  
4.2.1 the ability to manufacture batches of the material with evidence demonstrating a reproducible radiation-induced change,  
4.2.2 the availability of instrumentation for measuring this change, and  
4.2.3 the ability to take into account effects of influence quantities on the dosimeter response and on the measured absorbed-dose values.  
4.3 Dosimeter/dosimetry system characterization is conducted to determine the performance characteristics for a dosimeter/dosimetry system related to its capability for measuring absorbed dose. The information obtained from dosimeter/dosimetry system characterization includes the reproducibility of the measured absorbed-dose value, the useful absorbed-dose range, effects of influence quantities, and the conditions under which the dosimeters can be calibrated and used effectively.Note 4—When dosimetry systems are calibrated under the conditions of use, effects of influence quantities may be minimized or eliminated, because the effects can be accounted for or incorporated into the calibration method (see ISO/ASTM Practice 51261).  
4.4 The influence quantities of importance might differ for different radiation processing applications and facilities. For references to standards describing different applications and facilities, see ISO/ASTM Practice 52628.  
4.5 Classification of a dosimeter as a type I dosimeter or a t...
SCOPE
1.1 This guide provides guidance on determining the performance characteristics of dosimeters and dosimetry systems used in radiation processing.  
1.2 This guide describes the influence quantities that might affect the performance of dosimeters and dosimetry systems and that should be considered during dosimeter/dosimetry system characterization.  
1.3 Users of this guide are directed to existing standards and literature for procedures to determine the effects from individual influence quantities and from combinations of more than one influence quantity.  
1.4 Guidance is provided regarding the roles of the manufacturers, suppliers, and users in the characterization of dosimeters and dosimetry systems.  
1.5 This guide does not address how the dosimeter/dosimetry system characterization information is to be used in radiation processing applications or in the calibration of dosimetry systems.Note 1—For guidance on the use of dosimeter/dosimetry system characterization information for the selection and use of a dosimetry system, the user is directed to ISO/ASTM Practice 52628.Note 2—For guidance on the use of dosimeter/dosimetry system characterization information for dosimetry system calibration, the user is directed to ISO/ASTM Practice 51261.  
1.6 This guide does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
4.1 Ionizing radiation is used to produce various desired effects in products. Examples of applications include the sterilization of medical products, microbial reduction, modification of polymers and electronic devices, and curing of inks, coatings, and adhesives.
4.2 Absorbed-dose measurements, with statistical controls and documentation, are necessary to ensure that products receive the desired absorbed dose. These controls include a program that addresses requirements for calibration of routine dosimetry system.
4.3 A routine dosimetry system calibration procedure as described in this document provides the user with a dosimetry system whose dose measurements are traceable to national or international standards for the conditions of use (see Annex A4). The dosimetry system calibration is part of the user’s measurement management system.
SCOPE
1.1 This practice specifies the requirements for calibrating routine dosimetry systems for use in radiation processing, including establishing measurement traceability and estimating uncertainty in the measured dose using the calibrated dosimetry system.
NOTE 1—Regulations or other directives exist in many countries that govern certain radiation processing applications such as sterilization of healthcare products and radiation processing of food requiring that absorbed-dose measurements be traceable to national or international standards (ISO 11137-1, Refs (1-3)2).
1.2 The absorbed-dose range covered is up to 1 MGy.
1.3 The radiation types covered are photons and electrons with energies from 80 keV to 25 MeV.
1.4 This document is one of a set of standards that provides recommendations for properly implementing dosimetry in radiation processing, and describes a means of achieving compliance with the requirements of ASTM E2628 “Practice for Dosimetry in Radiation Processing” for the calibration of routine dosimetry systems. It is intended to be read in conjunction with ASTM E2628 and the relevant ASTM or ISO/ASTM standard practice for the dosimetry system being calibrated referenced in Section 2.
1.5 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
Radiation processing of articles in both commercial and research applications may be carried out for a number of purposes. These include, for example, sterilization of health care products, reduction of the microbial populations in foods and modification of polymers. The radiations used may be accelerated electrons, gamma-radiation from radionuclide sources such as cobalt-60, or X-radiation.
To demonstrate control of the radiation process, the absorbed dose must be measured using a dosimetry system, the calibration of which, is traceable to appropriate national or international standards. The radiation-induced change in the dosimeter is evaluated and related to absorbed dose through calibration. Dose measurements required for particular processes are described in other standards referenced in this practice.
SCOPE
1.1 This practice describes the basic requirements that apply when making absorbed dose measurements in accordance with the ASTM E10.01 series of dosimetry standards. In addition, it provides guidance on the selection of dosimetry systems and directs the user to other standards that provide specific information on individual dosimetry systems, calibration methods, uncertainty estimation and radiation processing applications.
1.2 This practice applies to dosimetry for radiation processing applications using electrons or photons (gamma- or X-radiation).
1.3 This practice addresses the minimum requirements of a measurement management system, but does not include general quality system requirements.
1.4 This practice does not address personnel dosimetry or medical dosimetry.
1.5 This practice does not apply to primary standard dosimetry systems.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

SIGNIFICANCE AND USE
4.1 Gamma, electron, and X-ray (bremsstrahlung) facilities routinely irradiate a variety of products such as food, medical devices, aseptic packaging and commodities (see ISO/ASTM Practices 51204 and 51431). Process parameters must be carefully controlled to ensure that these products are processed within specifications (see ISO 11137, Section 2.3). Accurate dosimetry is essential in process control (see ISO/ASTM Guide 51261). For absorbed dose measurements to be meaningful, the combined uncertainty associated with these measurements must be estimated and its magnitude quantified.
NOTE 1 - For a comprehensive discussion of various dosimetry methods applicable to the radiation types and energies discussed in this guide, see ICRU Reports 14, 17, 34, 35 and Refs (5, 6).
4.2 This guide uses the methodology adopted by the International Organization for Standardization for estimating uncertainties in dosimetry for radiation processing (see 2.3). ASTM traditionally uses the terms of precision and bias where precision is a measure of the extent to which replicate measurements made under specified conditions are in agreement and bias is a systematic error (see ASTM Terminologies E 170 and E 456, and Practice E 177). As seen from this standard, components of uncertainty are evaluated as either Type A or Type B rather than in terms of precision and bias. Error is different from Type A and Type B components of uncertainty.
4.3 Although this guide provides a framework for assessing uncertainty, it cannot substitute for critical thinking, intellectual honesty, and professional skill. The evaluation of uncertainty is neither a routine task nor a purely mathematical one; it depends on detailed knowledge of the nature of the measurand and of the measurement method and procedure used. The quality and utility of the uncertainty quoted for the result of a measurement therefore ultimately depends on the understanding, critical analysis, and integrity of those who contribute to the a...
SCOPE
1.1 This guide defines possible sources of uncertainty in dosimetry performed in gamma, X-ray (bremsstrahlung), and electron irradiation facilities and offers procedures for estimating the resulting magnitude of the uncertainties in the measurement of absorbed dose using a dosimetry system. Basic concepts of measurement, estimate of the measured value of a quantity, "true value", error, and uncertainty are defined and discussed. Components of uncertainty are discussed and methods are given for evaluating and estimating their values. How these contribute to the standard uncertainty in the reported values of absorbed dose are considered and methods are given for calculating the combined standard uncertainty and an estimate of expanded (overall) uncertainty. The methodology for evaluating components of uncertainty follows ISO procedures (see ). The traditional concepts of precision and bias are not used in this document. Examples are given in five annexes.
1.2 This guide assumes a working knowledge of statistics. Several statistical texts are included in the references  ().
This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.