24
SF₆ GAS MONITORING
The standard installation is for SF₆ density or pressure to be measured with the DSDP digital density sensor or PSDP digital pressure
sensor. These “digital” sensor types can only be wired to sensor input channels A, B or C. SF₆ temperature-compensated-pressure
can be measured with an SF₆ sensor that outputs a scaled milliamp signal. These “analog” sensor types can be wired to any sensor
input channel. The Mode for sensor types is found in the Sensors section of the Configuration page.
Figure 24
– Select Sensor Mode
The Optimizer3 can measure density with the DSDP sensor and calculate the equivalent gas pressure. It can also measure pressure
with the PSDP sensor and calculate the equivalent gas density. These calculations are based on entered SF₆ fill weight and fill
pressure values, taken from the breaker’s nameplate. A daily Density or Pressure Trend is calculated from the measured density
or pressure and temperature, using gas law equations. The daily trend is the decrease or increase per day in density or pressure,
averaged over a sliding 15-day period.