A method for detecting loss of SF6 gas from electrical utility apparatus determines a molar ratio of gas in a container at an initial time and of gas in the container at a subsequent time. Measurement of temperature is determined by averaging ambient temperature and temperature of the surface of the container. The initial values of pressure and temperature define the initial value of n as follows: n.sub.o=P.sub.gas o/T.sub.gas o The value at a subsequent time is n.sub.n=P.sub.gas n/T.sub.gas n The molar ratio can be defined as n.sub.n/n.sub.o or as n.sub.o/n.sub.n.
RELATED APPLICATIONS
This application is a continuation in part of Provisional Application 60/702,999 filed Jul. 7, 2005 and a continuation in part of Provisional Application 60/713,366 filed Sep. 2, 2005.
