Method for monitoring a leak rate in encapsulatedhigh voltage equipment

摘要

The method involves using a temperature compensated pressure sensor mounted on the external wall of metalclad gas insulated high voltage electrical equipment. The sensor is used to record gas densities (60) every six minutes during the four hours from midnight to 0400 hrs. For each of the four hours an average gas density (62) is produced and if the difference between two successive values (61) exceeds a preset threshold an alarm (A) is activated. An average of the four average gas density values for the four hours in the night period of each day is also produced to represent a daily average gas density (63) used to check annual changes (64).