Ground Isolator

[Osama]

I have an electronic contoller on my system. When I connect my controller to my PC ( to download data onto my PC) the last readings change in value dramatically. Like pH goes from actual 8.3 to 11.7. I am told I need a ground isolator to break the ground loop between my PC and the controller. Any one familiar with this situation and how did they remedy it. Are such isolators located in local stores like Radio Shack....

 

[Len]

Radio Shack carries them. A search turned up: Ground LP Isolator (270-0054)

 

[Osama]

Thanks Leonard: I will check with the local Radio Shack and see if what they carry wil work
Osama