Density monitoring of high voltage SF6 circuit breakers

As a circuit breaker ages it becomes more susceptible to SF₆ leaks. Retrofitting density monitoring equipment to existing circuit breakers allows for the early detection of a SF₆ leak before a low pressure alarm is raised. This report analyses different aspects of density monitoring which need to be considered to successfully retrofit a SF₆ circuit breaker with density monitoring equipment. These aspects include sampling rate, what type of transducer to use and how to interpret the density measurements to detect SF₆ leaks.