Instruments and equipment are one of the important tools for laboratories to carry out testing. The accuracy and validity of testing data will directly affect the correctness and legal effect of the testing reports issued. The instrument and equipment must ensure accuracy on the one hand, and continuous and stable operation on the other. However, due to the inherent mechanical, optical, electrical and electronic characteristics of the instrument and equipment, it is prone to component damage, data drift and other phenomena. At this time, the accuracy and reliability of the instrument can be judged through periodic inspection.
The so-called interim verification refers to checking the system drift of instruments and equipment in order to maintain the confidence of their calibration status. Interim verification is not calibration. What instruments and equipment in the laboratory need to be verified during the period? What is the verification method for the period verification? Next, we will have a thorough understanding of laboratory equipment during the inspection.
In order to complete a large number of inspection tasks, testing agencies often have to configure various instruments and equipment. In order to ensure the accuracy of the test results, the credibility of the equipment is very important. In addition to ensuring the reliability of instruments and equipment through control of procurement, calibration, etc., testing agencies, period verification is also an important method. At the same time, it is a requirement in the standard and is also a quality management required for national laboratory accreditation and metrology certification. One way.
Which instruments and equipment in the laboratory need to be checked during the period?
Whether the equipment needs to be checked during the period should be based on factors such as the possibility of problems in the actual situation, the severity of the problems, and the quality traceability costs that may be brought about, and a reasonable determination of whether the period check is required.
Usually considered from the following aspects:
1. The stability of the equipment: For equipment that is not stable enough, easy to drift, and easy to age, periodic inspections should be carried out.
2. Equipment usage status and frequency: for frequently used instruments and equipment; instruments and equipment that are frequently disassembled, transported, and carried to the site for testing; instruments and equipment that use harsh environments, have high failure rates or have been overloaded or suspected of quality problems ; Apparatus and equipment whose service life is approaching expiration shall undergo periodic inspection.
3. Calibration data analysis: According to the analysis of the changes in the calibration data over the years, it is judged whether the periodical inspection should be carried out. So which equipment can not be checked during the period? Generally, for equipment with good stability, equipment with low frequency of use, equipment with self-calibration function and self-calibration before each experiment, and chemical analysis instruments with standard samples each time, it is not necessary to consider the periodical verification.
Different laboratories have different requirements for verification during the period of measuring equipment. According to I, calibration laboratories and statutory metrological verification agencies must conduct periodic verification of their measurement standards and reference materials. For other measuring equipment and general measurement equipment of testing laboratories, periodic verification is required for those with high frequency of use and harsh environment. , Those that have a significant impact on the test results, those used for mobile use, those with greater drift and poor stability, those used for on-site testing, those that have been overloaded or suspected of quality problems.
Interim verification is not a recalibration, but certain methods of calibration can be used for interim verification. The sources of specific methods are generally as follows:
1. The verification method is specified in the testing standard. Many standard methods have specified calibration and other methods and requirements in detail, which can be directly used as a method of period verification.
2. Apparatus and equipment verification or calibration procedures. The instrument and equipment verification or calibration procedures often specify the entire verification process in detail. During the verification, the part that requires verification can be used. If there is no such instrument, the verification procedures for equipment can also refer to the verification procedures for similar instruments.
3. Instructions for use of the equipment or methods provided by the supplier.