Detailed explanations of measurement-related concepts
Verification
Verification, in essence, is a rigorous and important procedure. Its core purpose is to ascertain and confirm whether the measuring instruments meet the legal requirements. In the system of value transfer and traceability, verification occupies a crucial link. It is like a precise track, ensuring that the values of measuring instruments can be accurately transferred and traced.
The scope of verification is clearly defined, mainly focusing on the measuring instruments subject to compulsory verification as stipulated in the Catalogue of Measuring Instruments under Legal Management of the People's Republic of China. These instruments often play a crucial role in fields such as social life, industrial production, and scientific research. Conducting compulsory verification on them is the cornerstone for ensuring the stability of the entire social measurement order.
Verification work must be carried out strictly in accordance with the metrological verification regulations. This set of regulations is like a precise operation manual, specifying various details such as verification methods, steps, and environmental requirements. After the verification process is completed, a clear determination of whether the measuring instrument is qualified or not needs to be given, which is an important manifestation of the results of the verification work. Moreover, in order to ensure that the measuring instruments are always in an accurate and reliable state, verification should also be carried out in accordance with the cycle specified in the metrological verification regulations. Periodic verification can promptly detect possible deviations and problems of the measuring instruments.
Calibration
Calibration is a set of specific operations carried out under specified conditions. Its main task is to determine the relationship between the indicated values of measuring instruments and the corresponding values reproduced by measurement standards. Within the overall framework of value transfer and traceability, calibration is also an indispensable method.
The scope of calibration mainly covers non-compulsory verification measuring instruments specified in the Catalogue of Measuring Instruments under Legal Administration of the People's Republic of China. There are clear priorities for the selection of calibration bases. First, national calibration specifications should be preferentially selected because they have been strictly demonstrated and verified through practice, and are authoritative and scientific. If there are no national calibration specifications, calibration technical conditions can also be prepared according to metrological verification regulations or relevant product standards, user manuals and other technical documents. However, this requires the approval of the technical director of the technical institution to ensure the rationality and reliability of the calibration basis.
Calibration work is different from verification. It only provides data or curves indicating the deviation from the indicated values, and there is no need to judge whether the instrument is qualified or not. However, calibration also requires a calibration cycle, and the accuracy and stability of measuring instruments are ensured through periodic calibration.
Testing is a technical operation targeting given objects. These objects cover multiple fields such as products, materials, equipment, organisms, physical phenomena, processes or services. The testing process is carried out in accordance with the specified procedures, and its core task is to determine one or more characteristics or performances.
It can be clearly seen from the definition of testing that "testing" is merely a technical operation. Its focus lies in operating in accordance with the specified procedures and providing the measured results. Throughout the entire process, there is no need to judge whether the measured data are qualified or not. Its main purpose is to obtain objective measurement data.
Inspection
Inspection is a comprehensive activity. It assesses one or more characteristics of an entity by using various means such as measurement, examination, testing, and gauging. After obtaining relevant data, it is also necessary to carefully compare these results with the specified requirements to determine the compliance status of each characteristic.
Different from testing, "inspection" not only needs to provide data, but more importantly, it is necessary to make a judgment on whether it is qualified or not after comparison with the specified requirements. This judgment result is of great significance for aspects such as product quality control and service quality evaluation.
Assessment and accreditation of metrology-related institutions
Assessment of legal metrological verification institutions
The assessment of legal metrological verification institutions is an important task carried out by the government's metrological administrative department. Its target is the metrological verification institutions established legally or authorized. The assessment content covers all aspects of the institutions, and it is a comprehensive and strict assessment.
This assessment has the attribute of mandatory requirements, which reflects the strictness and standardization of the government's management of metrological verification institutions. Its main assessment basis is JJF1069 - 2003 "Assessment Specification for Legal Metrological Verification Institutions", which provides detailed standards and requirements for the assessment work.
The assessment work is organized and implemented by the national and provincial government metrology administrative departments. Once the assessment is passed, a certificate and a special seal for verification/calibration will be issued, which is an official recognition of the capabilities of the metrology verification institution. For the projects approved through the assessment, the institution can carry out metrology verification and calibration work in accordance with the current metrology verification regulations and calibration specifications. The assessment cycle is 5 years. After the expiration, a re - assessment is required. During the cycle, supervision and review can also be appropriately conducted according to the actual situation to ensure that the institution always maintains a good operating state and professional capabilities.
Accreditation of testing and calibration laboratories
Accreditation of testing and calibration laboratories is an assessment of the specific capabilities of testing and calibration laboratories. It mainly evaluates whether a laboratory has the capabilities for a certain type of testing and calibration.
Different from the assessment of legal metrological verification institutions, the accreditation of testing and calibration laboratories is a voluntary act. Whether it is a first - party, second - party or third - party testing and calibration laboratory, as long as there is a need, it can apply. The main assessment basis is GB/T15481 - 2000 "General requirements for testing and calibration laboratories" or CNAL/AC01 - 2000.
The assessment work is organized by the China National Accreditation Board for Laboratories with experts. If a laboratory passes the assessment, it will be issued a national laboratory accreditation certificate and allowed to use the "CNAL" accreditation mark. This mark represents that the laboratory has the corresponding testing and calibration capabilities and professional levels. The assessment cycle is also 5 years. After expiration, a re - assessment is required to ensure that the laboratory continuously meets the accreditation requirements.
Metrological certification
Metrological accreditation is an assessment carried out by the national government's metrological administrative department on the capabilities of product quality inspection institutions. Its core purpose is to ensure that the fair data issued by quality inspection institutions to society are accurate and reliable, which is of great significance in safeguarding market order and protecting the rights and interests of consumers.
Metrological certification is a mandatory government action, which reflects the government's determination and efforts in product quality supervision. The assessment work is organized and implemented by the Certification and Accreditation Administration of the People's Republic of China and local administrative departments. Metrological certification is mainly based on the Document No. [2000]046, "Evaluation Criteria for Metrological Certification/Review and Approval (Acceptance) of Product Quality Inspection Institutions" issued by the Quality and Technical Supervision Certification Department, and GB/T 15481 - 2000 "General Requirements for the Competence of Testing and Calibration Laboratories".
If the quality inspection institution passes the assessment, it will be issued a measurement certification certificate and allowed to use the "CMA" standard seal. This seal is an important symbol that the quality inspection institution has the corresponding capabilities and qualifications. The assessment cycle is 5 years. After the expiration, a re - review is required to ensure that the quality inspection institution continuously has the ability to provide accurate and reliable data for society.
Review and approval
Review and accreditation is a capacity assessment carried out on quality supervision and inspection institutions established and authorized in accordance with the law. The main responsibility of these institutions is to provide fair data for society, and their work plays a crucial role in ensuring product quality and market order. Review and accreditation is a mandatory government action, which reflects the government's strict management of quality supervision and inspection work.
The assessment work is organized and implemented by national, departmental, and local government departments. The focus of the assessment lies not only in testing the capabilities of the institutions but also in authorizing them to exercise the responsibility of product supervision on behalf of the state. The main assessment basis is the document No. [2000]046 issued by the Quality and Technical Supervision Certification Department and GB/T15481 - 2000.
If the inspection agency passes the assessment, it will be issued a Product Quality Inspection Agency Assessment Certificate (Acceptance Certificate) and an Authorization Certificate, and be allowed to use the "CAL" logo. This series of certificates and logos represent that the inspection agency has the corresponding capabilities and qualifications and can play an important role in the field of quality supervision and inspection. The assessment cycle is 5 years. After the expiration, a re - assessment is required to ensure that the inspection agency continuously maintains a good working state and professional capabilities.