Brain drain. The reason for the serious shortage of training for metrological verification personnel is the brain drain. Metrological verification personnel refer to those who have passed the examination and obtained the certificate of metrological verification personnel and engaged in metrological verification, calibration or testing in metrological technical institutions. Their main duties are: to be responsible for the internal calibration of the company, and to be responsible for the verification of all measuring equipment in the whole society in the Technical Supervision Bureau.