从UL1082上截取的:
29 Resistance of Grounding Test
29.1 The resistance between the point of connection of the equipment-grounding means at or within the
appliance and any other point in the grounding circuit of the appliance shall not exceed 0.1 ohms.
29.2 Compliance with the requirement in 29.1 is to be determined by:
a) A resistance-measuring instrument, or
b) Passing an alternating current of at least 25 amperes from a power supply of not more than
12 volts from the grounding pin of the attachment plug cap to a point in the grounding circuit,
and then measuring the resulting drop in potential between the two points. The resistance in
ohms is to be determined by dividing the drop in potential in volts by the current in amperes
passing between the two points.