All of the measurement & test equipment shall verified after verification and calibration to ensure that the measuring equipment meets the use requirements.Becasue the measurement equipment determined and calibrated by the company's internal self inspection has been confirmed that its measurement characteristics meet the use requirements when it is applied for purchase, if the self inspection is qualified or the self calibration parameters meet the requirements of the calibration specification, it will be deemed to meet the use requirements, and no separate verification mark will be carried out. When the use requirements change, it needs to be re verified. The measuring equipment for external verification / calibration shall be put into use after the user compares the certificate data with the use requirements, verifies that the measuring equipment meets the use requirements, and gives the verification mark.