Selection of Legal Metrological Institutions for Instrument Calibration and Validity Judgment of Calibration Certificatesг┐

Selection of Legal Metrological Institutions for Instrument Calibration and Validity Judgment of Calibration Certificates

In many fields such as scientific measurement, industrial production, medical testing, and scientific research, instrument calibration is an important means to ensure the accuracy and reliability of measurement. However, how to select a suitable legal metrological institution for instrument calibration and how to judge the validity of the calibration certificate often becomes a problem faced by many users. This article will discuss these two aspects of the problem.

1. Selection of Legal Metrological Institutions

The legal metrological institution refers to a metrological technical institution legally established, with corresponding metrological capability, able to issue legal metrological verification certificates or calibration certificates, and whose metrological capability has been recognized by the national or local metrological administrative departments. When selecting a legal metrological institution, several factors should be considered:

Qualifications and capabilities: The legal metrological institution should have the corresponding qualifications and capabilities to provide the required calibration services. It can be checked whether it has relevant metrological certification certificates, such as CNAS (China National Accreditation Service for Conformity Assessment) or CMA (China Metrological Certification). In addition, it can also be queried on the official website for the services provided, charging standards, and other information for comparison and selection.

Professionalism: Choosing a metrological institution with strong professionalism, rich experience, and strong technical strength can ensure the quality and efficiency of instrument calibration work. It can be understood by checking its service cases, customer evaluations, and other ways to understand its performance in similar services.

Credibility: Choosing a metrological institution with good credibility can reduce the risk of cooperation. Credibility can be understood through online inquiries, word-of-mouth recommendations, and other ways.

Price and service: Price is one of the important factors to consider when selecting a legal metrological institution. At the same time, the service content provided should also be considered, including on-site service, technical support, etc.

Secondly, the judgment of the validity of the calibration certificate

The validity of the calibration certificate is mainly reflected in whether its content is complete, whether the data is accurate, and whether the format is standardized. Specifically, it can be judged from the following aspects:

Format of calibration certificate: The calibration certificate issued by the legal metrological institution should have a unified format, including the name of the institution, certificate number, calibration item, calibration date, calibration result, and other information. At the same time, the certificate should be stamped with the special calibration seal of the institution and signed by the authorized signatory.

Accuracy of calibration certificate: The data in the calibration certificate should be accurate and error-free, including measurement results, measurement uncertainty, and other information. If it is found that there are anomalies or unreasonable aspects in the data, it should be immediately questioned to the metrological institution and require it to verify and correct.

Completeness of calibration certificate: The calibration certificate should contain all necessary information, such as measurement range, calibration basis, calibration method, etc. If some key information is missing, it should be questioned to the metrological institution and require it to supplement the completeness.

Traceability of calibration certificate: The calibration certificate should have traceability, that is, it can trace back to the original data and calibration process through the information on the certificate. If it is found that the certificate cannot trace back to the original data or calibration process, it should be questioned to the metrological institution and require it to provide complete calibration records.

Validity of calibration certificate: The validity of the calibration certificate is usually reflected by its validity period. The legal metrological institution should clearly specify the validity period of the calibration certificate and mark it on the certificate. If it is found that the calibration certificate has expired, it should be immediately questioned to the metrological institution and require it to recalibrate.

When selecting a legal metrological institution for instrument calibration, it is necessary to fully consider the aforementioned factors and carefully compare during the selection process to ensure that a metrological institution with the corresponding qualifications, capabilities, professionalism, and credibility is chosen. At the same time, during the process of judging the validity of the calibration certificate, attention should be paid to aspects such as format, accuracy, completeness, traceability, and validity to ensure the quality and reliability of the calibration work.