4 Preparations and Preconditions.4.1 Preconditions: Insulators have been installed in place, and the cleaning for them has been completed.4.2 List of main test instruments4.3 Requirement: All test instruments shall be calibrated valid.
4 Preparations and Preconditions.<br>4.1 Preconditions: Insulators have been installed in place, and the cleaning for them has been completed.<br>4.2 List of main test instruments<br>4.3 Requirement: All test instruments shall be calibrated valid.