Patent ID: 7257496

Claim:
A method for detecting loss of SF6, also known as sulfur hexafluoride, gas from electric utility apparatus comprising the steps of: taking measurements at a beginning time and a later time; wherein taking measurements comprise the steps of: detecting pressure of a gas containing SF6, also know as sulfur hexafluoride, in a container which encloses an electric utility apparatus; detecting ambient temperature where the electric utility apparatus is located; detecting temperature of an outer surface of the container, and computing an average of the ambient temperature and the temperature of an outer surface of the container; computing a molar ratio using pressure and the computed average temperature measurements taken at the beginning time and the later time; and wherein SF6, also known as sulfur hexafluoride, gas loss from the electric utility apparatus is detected by comparing molar ratio between measurements taken at the beginning time and the later time, and conveying SF6, also known as sulfur hexafluoride, loss to a operator.