Laboratory instrument grounding line can be dug on the ground at the window of a one-meter-square pit, in the pit into a 2-inch galvanized pipe (more than 1.5 meters long, the longer the better), the upper end of the weld on a M10 Rose, press a 2.5mm2 copper wire into the room to do with the ground can be.
(Sprinkle some salt in the earth pit and bury it)