OK, I took the liberty of going to the Davis site to get the info on their isolator kit. Hope this helps you out .
Weather here sucks.
Freezing mist, ice, then will melt and get snow on top. For upgraded protection against the electrical disturbances caused by ground offsets or static charges, install the Link Isolator Kit between the WeatherLink data logger and your computer. Recommended when the console and the computer are not grounded or are connected to two different grounds. For use with the Perception, Weather Wizard III, and Weather Monitor II only.