A method of operating a wind turbine. The measuring system comprises a modular display and adjustment unit and a modular low power sensor unit. In one example, a bearer may be selected based on a determination that other bearer are not configured to support uplink data packet transmissions. In one implementation, processes are described for pH’s of 7. In addition a capability is provided for input and output from the device, such as output to stereo headphones. The control circuit compares ground fault current of either polarity flowing through the sense resistor to a prescribed value.