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Comparison Table for the Revision of CNAS-CL01-G002 \"Requirements for Metrological Traceability of Measurement Results\" – Clauses (based on 2021 version): 2018, 2021. Changes: Preface. The requirements for metrological traceability specified in this document are in line with the Joint Statement on Metrological Traceability by BIPM, OIML, ILAC, and ISO issued jointly in 2011, as well as ILAC-P10:2013 \"ILAC Policy on Traceability of Measurement Results\". The requirements for metrological traceability specified in this document are in line with the Joint Statement on Metrological Traceability by BIPM, OIML, ILAC and ISO, jointly issued in 2018, as well as ILAC-P10:2020, ILAC’s Policy on Traceability of Measurement Results. Revised document version Preface This document replaces CNAS-CL06:2014 \"Requirements for Traceability of Measurement Results\". This document is a revised edition of CNAS-CL01-G002:2018 \"Requirements for Metrological Traceability of Measurement Results\". Language description changes. Preface: This revision is mainly based on the changes in CNAS-CL01:2018 \"Criteria for the Accreditation of Testing and Calibration Laboratories\"; certain contents have been updated, the titles and content of the document have been edited, and the document numbers have been adjusted in accordance with CNAS’ unified requirements. This revision mainly updates aspects such as the scope, normative reference documents, terms, and definitions in light of the changes in ILAC-P10:2020, \"ILAC’s Policy on Metrological Traceability of Measurement Results\". Basis and Scope of Revision 1 Scope: This document specifies the requirements regarding the metrological traceability of measurement results that are applicable to CNAS’s accreditation activities for organizations such as testing laboratories (including medical laboratories), calibration laboratories, inspection bodies, producers of reference materials/standards, and providers of capacity testing (hereinafter collectively referred to as conformity assessment bodies). This document specifies the metrological traceability requirements for measurement results that CNAS applies when carrying out accreditation activities for testing laboratories (including medical laboratories), calibration laboratories (including medical reference measurement laboratories), testing agencies, producers of reference materials/standard samples, biological sample banks, and proficiency testing providers (hereinafter collectively referred to as conformity assessment bodies). Scope: This document applies to testing (including medical testing) and calibration activities, as well as to conformity assessment activities involving measurement such as inspection, production of reference materials/standard samples, and proficiency testing. This document applies to the metrological traceability of testing (including medical testing) and calibration (including medical reference measurements), as well as to the conformity assessment activities related to measurement carried out by testing laboratories, producers of reference materials/standards, biological sample banks, and proficiency testing providers. Increase by 1. This document specifies the metrological traceability requirements for measurement results obtained by accreditation bodies through external agencies. The internal calibration carried out by the testing laboratory shall comply with CNAS-CL01-G004 \"Requirements for Internal Calibration\". The internal calibration carried out by the testing laboratory shall comply with the requirements specified in CNAS-CL01-G004 \"Requirements for Internal Calibration\". Delete 2. Normative reference documents: The following documents are essential for the application of this document. For referenced documents dated, only the version dated applies to this document. For reference documents without a date, the latest version (including amendments) applies to this document. The contents of the following documents constitute indispensable provisions of this document through normative references therein. Among them, for reference documents dated, only the version corresponding to that date is applicable to this document ； For reference documents without a date, the latest version (including all amendment sheets) applies to this document. Changes in the textual description 2 Normative reference documents 2.1 CNAS-CL01 \"Criteria for the accreditation of testing and calibration laboratories\" CNAS-CL01:2018 \"Criteria for the accreditation of testing and calibration laboratories\" – the version number was added, while the article numbers were removed. 2 Normative reference documents 2.2 ILAC-P10:2013 \"ILAC Policy on Traceability of Measurement Results\" ILAC-P10:2020 \"ILAC Policy on Metrological Traceability of Measurement Results\" – the version number was updated, and the article numbers were removed. 2 Normative reference documents 2.3 ISO/IEC Guide 99 \"Vocabulary of International Metrology – Basic and General Concepts and Related Terms (VIM)\" ISO/IEC Guide 99 \"Vocabulary of International Metrology – Basic and General Concepts and Related Terms (VIM)\" – the article numbers were removed. 3 Terms and definitions This document uses the relevant terms and definitions from VIM. The terms and definitions defined in VIM, as well as those listed below, apply to this document. Language description change 3.1 Metric traceability (VIM 2.41) is a property of measurement results that relates those results to reference objects through an unbroken chain of calibrations specified in the document; each calibration in this chain introduces measurement uncertainty. The property of measurement results whereby they are linked to a reference object through an unbroken chain of calibrations specified in a document; each calibration within this chain introduces measurement uncertainty. Unchanged 3.1 Metrological traceability (VIM 2.41) Note 1: The reference in this definition can be the definition of a practically realized measurement unit, a measurement procedure that includes non-ordinal measurement units, or a measurement standard. Note 1: The reference object in this definition can be the definition of a measurement unit that has been actually implemented, or a measurement procedure that includes non-ordinal measurement units, or a measurement standard. Unchanged 3.1 Metrological traceability (VIM 2.41) Note 2: Metrological traceability requires the establishment of a calibration hierarchy. Note 2: The requirements for metrological traceability mandate the establishment of a calibration hierarchy. Unchanged 3.1 Metrological traceability (VIM 2.41) Note 3: The technical specifications of the reference material must include the time at which it was used to establish the calibration hierarchy, as well as metrological information regarding that reference material, such as the time of the first calibration carried out within this calibration hierarchy. Note 3: The technical specifications of the reference object must include the time when the reference object was used in establishing the calibration level sequence, as well as metrological information regarding the reference object, such as the time when the first calibration was performed within this calibration level sequence. Unchanged 3.1 Traceability of measurements (VIM 2.41) Note 4: For measurements that have more than one input in their measurement model, each input value itself must be traceable, and the sequence of calibration levels can form a hierarchical structure or network. The efforts made to establish metrological traceability for each input value should be commensurate with its contribution to the measurement result. Note 4: For measurements that have more than one input in the measurement model, each input value itself must be traceable through metrological standards, and the calibration hierarchy can form a hierarchical structure or network. The efforts made to establish metrological traceability for each input value should be commensurate with its contribution to the measurement result. Unchanged 3.1 Metrological traceability (VIM 2.41) Note 5: The metrological traceability of measurement results does not guarantee that their measurement uncertainties meet the specified requirements, nor does it ensure the absence of errors. Note 5: The metrological traceability of the measurement results does not guarantee that their measurement uncertainty meets the specified requirements, nor does it ensure the absence of errors. Unchanged 3.1 Measurement traceability (VIM 2.41) Note 6: If the comparison between two measurement standards is performed to verify one of them, and if necessary, to correct its value and determine the measurement uncertainty, then such a comparison may be regarded as calibration. Note 6: If the comparison between two measurement standards is used to verify one of them, and its value is corrected as necessary along with the measurement uncertainty being provided, then such a comparison can be regarded as calibration. Unchanged 3.1 Traceability in metrology (VIM 2.41) Note 7: The term “traceability” sometimes refers to “metrological traceability,” and at other times it denotes other concepts such as “sample traceability,” “document traceability,” “instrument traceability,” or “material traceability”; it denotes the history (“track”) of a particular item. Therefore, when there is a risk of confusion, it is best to use the full term “metrological traceability”. Note 7: The term “traceability” sometimes refers to “metrological traceability”, and at other times to other concepts such as “sample traceability”, “document traceability”, “instrument traceability”, or “material traceability”. Its meaning is the history (“trajectory”) of a particular item. Therefore, when there is a risk of confusion, it is best to use the full term “metrological traceability”. Unchanged 3.2 Reference Materials (RM) (VIM 5.13), also known as standard materials or reference samples, are substances with defined properties that are sufficiently homogeneous and stable; they have been shown to meet the intended requirements for measurement or verification of nominal properties. A substance with specified properties, sufficient uniformity, and stability, used as a reference, which has been proven to meet the intended purposes of measurement or verification of nominal properties. Unchanged 3.2 Reference Material (RM) (VIM 5.13) Note 1: The verification of nominal properties provides a nominal property value along with its uncertainty. This uncertainty is not a measurement uncertainty. Note 1: The verification of the nominal characteristic provides a nominal characteristic value and its uncertainty. This uncertainty is not a measurement uncertainty. Unchanged 3.2 Reference material (RM) (VIM 5.13) Note 2: Both assigned and unassigned reference materials can be used to control precision, but only assigned reference materials can be used for calibration or to control accuracy. Note 2: Referenced materials, whether assigned or not, can be used for controlling precision, but only assigned referenced materials can be used for calibration or controlling accuracy. Unchanged 3.2 Reference Material (RM) (VIM 5.13) Note 3: “Reference material” includes both materials with quantitative properties and those with nominal characteristics. Note 3: “Reference materials” include both substances with quantitative properties and those with nominal characteristics. Unchanged 3.2 Reference Material (RM) (VIM 5.13) Note 4: Reference materials are sometimes integrated with specially designed devices. Note 4: Reference materials are sometimes integrated with specialized devices. Unchanged 3.2 Reference materials (RM) (VIM 5.13) Note 5: Some reference materials have their assigned values traced to a unit of measurement outside the system of units; such materials include vaccines, for which the international unit (IU) has been specified by the World Health Organization (WHO). Note 5: Some reference materials have their assigned values traced to a unit of measurement outside the international system; such materials include vaccines, for which the international unit (IU) has been designated by the World Health Organization (WHO). Unchanged 3.2 Reference Material (RM) (VIM 5.13) Note 6: In a particular measurement, the given reference material can be used for either calibration or quality assurance only. Note 6: In a particular measurement, the given reference material can be used only for either calibration or quality assurance. Unchanged 3.2 Reference Material (RM) (VIM 5.13) Note 7: The instruction manual for the reference material shall include information on its traceability, indicating its source and processing procedures. Note 7: The instruction manual for the reference material shall include information on its traceability, indicating its source and processing procedures. Unchanged 3.3 Certified Reference Materials (CRM) (VIM 5.14), also known as certified standard materials or certified reference samples, are reference materials that come with documents issued by authoritative bodies, providing one or more characteristic values with uncertainties and traceability, obtained using valid procedures. 3.3 Certified Reference Materials (CRM) (VIM 5.14) has been removed. It includes documents issued by authoritative bodies, providing reference materials with one or more characteristic values that have uncertainty and traceability, obtained using valid procedures. Unchanged 3.3 Example of a certified reference material (CRM) (VIM 5.14): Human serum in which the cholesterol concentration value and its measurement uncertainty are specified, used as a calibrator or a material for controlling the accuracy of measurements, as indicated in the accompanying certificate. Example: In the attached certificate, human serum for which the assigned value of cholesterol concentration and its measurement uncertainty are given is used as a calibrator or a substance for controlling measurement trueness. Unchanged 3.3 Certified reference materials (CRMs) (VIM 5.14) Note 1: The “document” is provided in the form of a “certificate” (see ISO Guide 31). Note 1: The “document” is provided in the form of a “certificate” (see ISO Guide 31). Unchanged 3.3 Certified Reference Materials (CRM) (VIM 5.14) Note 2: The procedures for the production and calibration of certified reference materials are specified in standards such as ISO 17034 and ISO Guide 35. Note 2: The procedures for the production and calibration of certified reference materials are specified in ISO 17034 and ISO Guide 35. Delete 3.3 Certified Reference Materials (CRM) (VIM 5.14) Note 3: In this definition, “uncertainty” includes both “measurement uncertainty” and “uncertainty of the nominal characteristic values (such as identity and sequence).” “\"Traceability\" includes both \"the metrological traceability of measurement values\" and \"the traceability of nominal characteristic values.\" Note 3: In this definition, “uncertainty” includes both “measurement uncertainty” and the uncertainty of the nominal characteristic values (such as identity and sequence). “\"Traceability\" includes both \"the metrological traceability of measurement values\" and \"the traceability of nominal characteristic values.\" Unchanged 3.3 Certified Reference Materials (CRM) (VIM 5.14) Note 4: The specified values of \"Certified Reference Materials\" require metrological traceability of the measurement uncertainty. Note 4: The specified value requirements for “certified reference materials” must be accompanied by metrological traceability of the measurement uncertainty. Unchanged 3.4 **NMI**: In this document, the term “NMI” refers to both those National Metrology Institutes that maintain measurement standards at the global level (or within a region/economy), as well as other designated organizations. The **metrology institutes** mentioned in this document include both those that maintain measurement standards on a global scale (or at the regional or economic level), as well as other designated institutions (DI). The wording has been revised; 3.5 International Joint Committee on Traceability in Laboratory Medicine (JCTLM) has been added. The International Joint Committee on Traceability in Laboratory Medicine (JCTLM) was established jointly by the International Bureau of Weights and Measures (BIPM), the International Federation of Clinical Chemistry and Laboratory Medicine (IFCC), and the International Laboratory Accreditation Cooperation (ILAC). It provides a global platform to guide and promote recognized measurement equivalence in international medical testing, as well as the traceability of appropriate measurement standards. Add 4 approval requirements. 4.14.1 In accordance with Article 6.4.6 of CNAS-CL01, measurement equipment shall be calibrated under the following circumstances: 4.1 Measurement equipment shall be calibrated under the following circumstances: Delete 4.1 – When the measurement accuracy or measurement uncertainty affects the validity of the reported results, or a) When the measurement accuracy or measurement uncertainty affects the validity of the reported results ； And (or) Revised wording 4.1 — When establishing the metrological traceability of the reported results. b) To establish the metrological traceability of the reported results, calibration of the equipment is required. Add 4.1 Note: Device types that can affect the validity of the test results include: —— Devices used for directly measuring the quantity being tested, such as balances used to measure mass ； ——Devices used to correct measured values, such as for temperature measurement ； ——A device used to obtain measurement results by calculating from multiple quantities. Note: The types of equipment that can affect the validity of reported results include: — Equipment used for directly measuring the quantity being measured, such as using a scale to measure mass ； ——Devices used to correct measured values, such as for temperature measurement ； ——A device used to obtain measurement results by calculating from multiple quantities. Unchanged 4.24.2 The certification body shall develop a calibration plan for the measuring equipment that requires calibration, and carry out reviews and make necessary adjustments to maintain confidence in its calibration status. 4.2 The qualification assessment body shall develop a calibration plan for the equipment that requires calibration. This plan should include details such as the parameters to be calibrated, the range, requirements regarding measurement uncertainty, and the calibration frequency, so that specific and targeted traceability requirements can be specified when the equipment is sent for calibration. The conformity assessment body shall review the calibration plan and make necessary adjustments to maintain confidence in the calibration status of the equipment. 4.34.3 To establish and maintain the metrological traceability of measurement results, conformity assessment bodies shall evaluate and select traceability pathways that meet the relevant traceability requirements, and document them, to ensure that the metrological traceability of measurement results is linked to appropriate reference standards through an unbroken calibration chain. 4.3 To establish and maintain the metrological traceability of measurement results, accreditation bodies shall evaluate and select relevant organizations that meet the traceability requirements, and document this process to ensure that the metrological traceability of measurement results can be linked to appropriate reference objects through an unbroken chain of calibrations. Delete, revise wording: 4.44.4 The certification body shall ensure that measurement results can be traced to the International System of Units (SI) by the following means: 4.4 The certification body shall ensure that measurement results are traceable to the International System of Units (SI) by the following means: unchanged 4.4a) Calibration provided by a qualified calibration laboratory ； a) Calibration provided by a qualified laboratory ； Delete 4.4 Note: Calibration laboratories that meet the requirements of the ISO/IEC 17025 standard can be considered competent. Note: Calibration laboratories that meet the requirements of the ISO/IEC 17025 standard are considered competent. Revised wording 4.4b) Producers of reference materials with the necessary capabilities shall provide and declare the standard values of certified reference materials whose metrological traceability is to the SI ； b) The standard values of certified reference materials, provided by competent producers of reference materials/standard samples and declared to have metrological traceability to the SI ； Addition 4.4: Standard material producers that meet the requirements of ISO 17034 are considered competent. Note: Producers of reference materials/standards that meet the requirements of ISO 17034 are considered competent. Addition, revised wording: 4.4c) The direct reproduction of SI units shall be ensured by direct or indirect comparison with **or international standards. c) Direct reproduction of SI units, ensured by direct or indirect comparison with ** or international standards. Unchanged 4.5. CNAS recognizes the metrological traceability of calibration or verification services provided by the following institutions: Unchanged 4.5. a) The National Institute of Metrology, China, or other NMIs that have signed the International Committee for Weights and Measures (CIPM) “Mutual Recognition Arrangement concerning Metrological Standards and Calibration and Measurement Certificates Issued by NMIs” (CIPM MRA); the calibration services provided by these NMIs within the scope of mutual recognition. a) Calibration services provided by the National Institute of Metrology, China, or other NMIs that have signed the International Committee for Weights and Measures (CIPM) **Mutual Recognition Arrangement for National Measurement Standards and Calibration and Measurement Certificates issued by NMIs** (CIPM MRA), within the scope of mutual recognition. Unchanged. Note 4.5-1: The scope of mutual recognition for NMI’s is available in Appendix C of the BIPM Key Comparison Database (BIPM/KCDB) (URL: http://kcdb.bipm.org/appendixC/default.asp); it includes the measurement range and uncertainty. Note 1: The scope of mutual recognition for NMI can be found in Appendix C of the BIPM/KCDB database (website: http://kcdb.bipm.org/appendixC/default.asp), which includes the measurement range and uncertainty. Unchanged 4.5 Note 2: Some NMI use the CIPM MRA designation on their calibration certificates to demonstrate that their calibration capabilities fall within the scope of the CIPM MRA. However, using the CIPM MRA label is not mandatory; BIPM/KCDB remains the most accurate method for verification. Note 2: Some NMI use the CIPM MRA designation on their calibration certificates to demonstrate that their calibration capabilities fall within the scope of CIPM MRA mutual recognition, but the use of this designation is not mandatory; BIPM/KCDB remains the most accurate means of verification. Increase by 4.5. Note 3: The NMI of the Member States of the Metre Convention can be traced directly to BIPM; in KCDB, it can be automatically linked to the relevant calibration services provided by BIPM (including measurement ranges and uncertainties), as well as the calibration certificates issued by BIPM. Note 3: The NMI of the Member States of the Metre Convention can be directly traced back to BIPM; in KCDB, it can be automatically linked to the relevant calibration services provided by BIPM (including measurement ranges and uncertainties), as well as the calibration certificates issued by BIPM. Unchanged 4.5 Note 4: The calibration capabilities of the National Institute of Metrology of China have been recognized, and the scope of their recognition is expressed in accordance with the methodology for calibration and measurement capabilities (CMC) specified in BIPM/KCDB. A list of measuring instruments within the calibration capabilities of this institution is available on its website. Note 4: The calibration capabilities of the National Institute of Metrology of China have been recognized, and the scope of these recognition capabilities is expressed in accordance with the framework for calibration and measurement competence (CMC) specified by BIPM/KCDB. A list of measuring devices within the calibration capabilities of this institution is available on its website. Unchanged 4.5b) Calibration services provided within the scope of their accreditation by a calibration laboratory that is CNAS-accredited, or accredited by an accreditation body that has signed the ILAC MRA. b) Calibration services provided within the scope of their accreditation by calibration laboratories that are accredited by CNAS, or by accreditation bodies that have signed the ILAC MRA or regional mutual recognition agreements recognized by ILAC. Add, delete Note 4.5: At the time this document was prepared, the regional accreditation bodies that had signed the ILAC MRA were the Asia-Pacific Laboratory Accreditation Cooperation (APLAC), the Inter-American Accreditation Cooperation (IAAC), and the European Accreditation Cooperation (EA). Some accreditation bodies only sign the mutual recognition agreements of the aforementioned regional cooperation organizations, but not the ILAC mutual recognition agreements; the calibration services provided by the calibrated laboratories accredited by such bodies are also recognized. Note 1: At the time this document was prepared, the regional accreditation bodies that had signed the ILAC MRA were the Asia-Pacific Accreditation Cooperation (APAC), the Inter-American Accreditation Cooperation (IAAC), the European Accreditation Cooperation (EA), the Arab Accreditation Organization (ARAC), and the African Accreditation Organization (AFRAC). Some accreditation bodies only sign the mutual recognition agreements of the aforementioned regional accreditation cooperation organizations, but not the ILAC mutual recognition agreement; the calibration services provided by the calibrated laboratories accredited by such bodies are also considered recognized. Revise the name and add Note 2 to 4.5: The calibration certificates of calibration laboratories may use the ILAC MRA joint mark, an endorsement signed under the ILAC MRA, or the endorsement mark of an accreditation body under a regional recognition cooperation agreement recognized by ILAC, in order to demonstrate that their calibration services fall within the scope of mutual recognition and to serve as evidence of metrological traceability. Add 4.5c) The statutory metrology institutions in our country carry out inspections on measuring instruments that are subject to mandatory verification in accordance with relevant laws and regulations. The conformity assessment body shall obtain and retain the qualification certificate and scope of authorization of the statutory metrological institution. “A “certification certificate” usually contains traceability information; if it does not include information on the uncertainty of the measurement results, the conformity assessment body shall obtain or assess such uncertainty. c) The statutory metrology institution conducts inspections on measuring instruments subject to mandatory verification, within the scope of its authority and in accordance with relevant laws and regulations. The conformity assessment body shall obtain and retain the qualification certificate and scope of authorization of the statutory metrological institution. The “verification certificate” used for measurement traceability shall contain information such as detailed measurement results; if the measurement results do not include uncertainty data, the conformity assessment body shall obtain or assess such uncertainty. Delete, add, or revise descriptions and wording. Note 4.5: The measurement uncertainty of calibration results and information on their traceability are essential elements for demonstrating metrological traceability. Note 1: Measurement results and traceability information are essential elements for demonstrating metrological traceability. Revised terminology 4.5 Note 2: The term \"legal metrology institutions\" as used in this document refers to those institutions that have obtained the \"Metrology Authorization Certificate\" for legal metrological verification issued by the competent metrology administration authority (based on the standards JJF 1069), as well as those institutions that have received administrative approval from the competent defense metrology authority for carrying out defense metrology activities. Note 2: The “legal metrology institutions” referred to in this document include those that have obtained the \"Metrology Authorization Certificate\" for legal metrological verification issued by the metrology administration authorities (based on the assessment standards JJF 1069), as well as those that have received administrative approval from the defense metrology authorities as defense metrology technical institutions. Unchanged 4.5d) When the traceability bodies specified in a) to c) are not available, traceability can also be established to the statutory metrology institutions in our country, or to other institutions authorized by the metrology administrative authorities, which provide calibration services within the scope of their authorization; the “calibration certificates” issued by such institutions should include at least traceability information, the calibration results, and the measurement uncertainty of those results. d) When the traceability institutions specified in a) to c) are unavailable, traceability can be achieved through the calibration services provided by China’s statutory metrological institutions within their authorized scope; the “calibration certificates” issued by these institutions shall include at least information on traceability and measurement results. Delete and revise the description 4.5e): When the traceability bodies specified in a) to d) are all unavailable, the conformity assessment body may choose the calibration services of other bodies that can ensure metrological traceability. At this time, the conformity assessment body shall retain at least the following traceability evidence that meets the relevant requirements of CNAS-CL01: e) When the traceability bodies specified in a) to d) are unavailable, the conformity assessment body may choose calibration services provided by other bodies that can ensure metrological traceability. At this time, the conformity assessment body shall retain at least the following traceability evidence that meets the relevant requirements of CNAS-CL01:2018: add 4.5·Records of calibration method validation ； ——Confirmation record of calibration method ； Unchanged 4.5·Procedure for evaluating measurement uncertainty ； ——Procedure for evaluating measurement uncertainty ； Revised terminology 4.5·Documents or records related to measurement traceability ； ——Documents and records related to the metrological traceability of measurement results ； Addition, revision of wording 4.5·Documents or records related to quality assurance of calibration results ； ——Documents and records to ensure the validity of calibration results ； Revised wording 4.5·Documents or records related to personnel capabilities ； ——Documents and records related to personnel capabilities ； Revised terminology 4.5 —— Equipment records that affect laboratory measurement results ； Add 4.5·Documents or records related to facilities and environmental conditions ； ——Documents and records related to facilities and environmental conditions ； Revised wording 4.5·Audit records of calibration service providers. ——Audit records of the calibration service provider (including evaluations of external suppliers and internal audit records). Added 4.64.8: When establishing traceability using RM, accreditation bodies shall select the following RM: 4.6: When establishing metrological traceability using RM, accreditation bodies shall select the following RM: Added 4.6a) CRM produced by NMI and falling within the scope of BIPM/KCDB ； a) CRM produced by NMI and within the scope of BIPM/KCDB ； Unchanged 4.6b) RM produced within the scope of accreditation by an RMP that is CNAS-accredited, or accredited by an accrediting body that has signed an APLAC MRA (RMP); b) Revised wording for CRM: produced within the scope of accreditation by an RMP that is CNAS-accredited, or accredited by an accrediting body that has signed an ILAC MRA or an ILAC-approved regional mutual recognition agreement, with addition of 4.6c) CRM published in the JCTLM database ； c) CRM published in the database of the Joint Committee on Traceability in Laboratory Medicine (JCTLM) ； Add 4.6d) CRM approved by the national metrology administrative authority ； d) **CRM approved by the administrative department in charge of metrology ； Unchanged 4.6e) CRM approved by the standardization administrative authority of our country. e) **CRM approved by the administrative department in charge of standardization. Unchanged 4.6 When the aforementioned RM is not available, the conformity assessment body may also select other appropriate RMs based on the measurement methods, while retaining traceability information. When the aforementioned RM is not available, the conformity assessment body may select an appropriate RM based on the measurement method and intended use, while retaining traceability information and evidence of RMP capability. Increase by 4.6. Note: For the selection and use of RMs, reference can be made to ILAC G9 \"Guidelines for the Selection and Use of RMs\", APLAC TC012 \"Guidelines for the Selection of Chemical RMs and Commercial Chemical Reagents for Calibration in Chemical Testing\", ISO Guide 33:2015 \"Reference Materials – Use of Reference Materials\", as well as the relevant standards in China’s GB/T 15000 series of standards. Note: The selection and use of RM can refer to ISO Guide 33:2015 \"Reference materials — Use of reference materials\", as well as the relevant standards in China’s GB/T 15000 series of standards. Delete 4.74.6: When it is technically not possible to trace measurements to SI units, the conformity assessment body shall demonstrate traceability to an appropriate reference standard by means of the following approaches, such as: 4.7 When it is technically not possible to trace measurements to SI units, the conformity assessment body shall prove traceability to an appropriate reference object; for example, revise the wording and delete 4.7a) The standard values of certified reference materials provided by standard material producers with the necessary capabilities ； a) Standard values of certified reference materials provided by competent producers of reference materials/standard samples ； Increase 4.7b) Use reference measurement procedures, specified methods, or clearly described protocol standards, such that the measurement results meet the intended purpose and are ensured through appropriate comparison. b) Results of clearly described reference measurement procedures, specified methods, or protocol standards that meet the intended purpose and are guaranteed through appropriate comparison. The evidence used for comparison shall be reviewed by an accredited institution. Revise the description and add Note 1 to 4.7: When it is technically not possible to measure and trace back to SI units, the quantity being measured must be clearly defined. To establish metrological traceability, it is necessary to provide evidence of comparing the characteristic being measured and the results with appropriate reference objects. Comparison is based on the premise that the measurement procedures have been fully validated and/or verified, the measuring equipment is properly calibrated, the measurement conditions (such as environmental conditions) are fully controlled, and reliable results can be obtained. Increase by 4.7 Note 2: Samples remaining from proficiency testing are often available, but it is necessary to check whether the proficiency testing provider (PTP) can supply additional stability information to demonstrate the consistent stability of the characteristic values of those samples and of the matrix. If PTP does not provide stability information, the proficiency testing samples remaining cannot be used to ensure the validity of the measurement results. 4.84.7 When the measurement results are traced back to recognized or agreed-upon measurement methods/standards, the conformity assessment body shall provide evidence regarding the origin of such methods/standards and their traceability. 4.8 When the measurement results are traced back to recognized or agreed-upon measurement methods/standards, the conformity assessment body shall provide evidence regarding the origin of such methods/standards and their traceability. Unchanged 4.8 Example: In the field of medical laboratory accreditation, the routine measurement procedures recommended by manufacturers constitute recognized measurement methods/standards ； In the field of accreditation for medical reference laboratories, reference measurement procedures approved by the International Joint Committee on Traceability in Laboratory Medicine (JCTLM) are considered to be recognized examples of measurement methods/standards; in the context of accreditation for medical testing, the measurement procedures selected by manufacturers or those that are routinely used constitute recognized measurement methods/standards ； In the field of accreditation for medical reference measurement laboratories, the Reference Measurement Procedures recognized or issued by the Joint Committee on Traceability in Laboratory Medicine (JCTLM) are considered to be recognized measurement methods/standards. Revise wording, delete, add: 4.94.9 The certification body shall verify the documents (such as calibration certificates) that serve as evidence of metrological traceability. It is confirmed that it should include at least the following aspects (taking the calibration certificate as an example): 4.9 The accreditation body shall verify the evidence of metrological traceability, and the contents of such verification shall include at least the following aspects: deleted; 4.9a) Completeness and compliance of the calibration certificate added ； a) Integrity and standardization of the traceability certificate ； Revised wording 4.9b) Make a determination on compliance with the intended usage requirements based on the calibration results ； b) Assessment of the compliance between the traceability results and the expected usage requirements ； Delete, revise wording: 4.9c) Where applicable, adjust the relevant equipment based on the calibration results, apply calibration factors, or make corrections during use. c) Where applicable, adjust the equipment based on the traceability results or apply calibration factors, or make corrections during equipment use ； Revise the wording and add 4.9 d) to determine whether it is necessary to re-evaluate the measurement uncertainty for the projects carried out. Increase