Vaisala offers online monitoring of SF6 insulation in high-voltage equipment. The Vaisala Multiparameter Transmitter DPT145 combines online dew point monitoring with pressure measurement, creating a tool for assessing the condition of SF6 insulation continuously and in real-time.
Sulphur hexafluoride (SF6) is used as an insulating gas in transmission and distribution equipment such as switchgears and circuit breakers to prevent arcing during switch-offs and protect equipment from failures. The direct normalized pressure measurement of the Vaisala DPT145 detects leakages immediately, while online dew point measurement provides early warning on moisture issues, which affect the insulating properties of the gas and cause rapid deterioration.
The Vaisala DPT145 provides online monitoring of seven different parameters at once. It measures dew point, pressure and temperature directly, and provides calculated values for density, normalized pressure, dew point in atmospheric pressure and ppm.
When one single instrument monitors seven different parameters, fewer mechanical connections are needed, which reduces the risk of leakages. Savings can be achieved across the board in the form of smaller investment and installation costs, and less need for on-site servicing, for example.
Online monitoring is also environmentally friendly as it removes the need for sampling and ensures that no SF6 gas is released into the atmosphere.
The DPT145 will be introduced for the first time at selected trade shows in Japan, Germany and China during the next few months. The transmitter will be commercially available during the third quarter of 2011.