Specific differences between calibration and calibration of gas detectors
1. Different purposes
The purpose of calibration is to compare the measurement standards, evaluate the indication error of measuring instruments, and calibrate them to meet the measurement standard range, ensuring the accuracy of measurement values. This is a set of bottom-up measurement value traceability operations.
Verification purpose: To conduct a comprehensive evaluation of measuring instruments. This comprehensive evaluation belongs to the category of unified quantity values, and is a top-down process of quantity value transmission. Verification should evaluate whether measuring instruments meet the specified requirements. This requirement is the error range specified in the verification regulations for measuring instruments. Evaluate whether the error range of the measuring device is within the specified error range through verification.
2. Different properties
The verification work outside the catalog of calibration and mandatory verification is not mandatory and belongs to the voluntary traceability behavior of the organization. This is a technical activity that can evaluate the indication error of measuring instruments based on the actual needs of the organization, and determine the value of measuring instruments or reference materials. Organizations can specify calibration specifications or methods based on actual needs. Self prescribed calibration cycles, calibration labels, and records. For gas detectors, general calibration can be self calibrated or commissioned by gas detector manufacturers.
Compulsory verification is a mandatory law enforcement act and falls within the scope of legal metrology management. Among them, the verification regulations and agreed cycles are all carried out in accordance with legal requirements. Verification must be carried out at the designated legal metrological verification institution or authorized metrological technical institution's metrological department or legally authorized unit designated by the metrological administrative department of the government at or above the county level. According to the current situation in our country, most production and service organizations do not have certification qualifications, and in most cases, metrology institutes only have such qualifications.
3. Based on different
The main basis for calibration is the "Calibration Specification" developed by the organization based on actual needs. In the "Calibration Specification", the organization establishes its own requirements for calibration procedures, methods, calibration cycles, calibration records, and labeling. Therefore, the "Calibration Specification" is a guiding document for organizations to implement calibration.
The main basis for verification is the "Metrological Verification Regulations", which is a statutory technical document that must be followed for the verification of measuring instruments. Among them, regulations are usually made for the verification period, metrological characteristics, verification items, verification conditions, verification methods, and verification results of measuring and testing equipment. The metrological verification regulations can be divided into three types: national metrological verification regulations, departmental metrological verification regulations, and local metrological verification regulations. These regulations belong to metrological regulatory documents, and organizations have no authority to formulate them. They must be formulated by authorized metrology departments that have been approved. In the absence of verification regulations as a basis, departments and localities may temporarily formulate legally binding technical documents, known as temporary verification methods.
4. Different conclusions
The conclusion of calibration is only to evaluate the measurement error of the measuring device, ensuring the accuracy of the measurement value, and does not require a qualified or unqualified judgment. The calibration results can be presented in the 'Calibration Report'.
The verification must be based on the measurement error range specified in the "Verification Regulations", and the determination of whether the measuring device is qualified or unqualified must be given. Exceeding the measurement error range specified in the "Verification Regulations" is considered unqualified, and within the specified measurement error range is considered qualified. The result of the verification is to provide a "Verification Certificate of Conformity".
