| 摘要 |
There is described a device for indicating whether a conductive element has an electrical resistance equal to or less than a predetermined value or whether the conductive element is reliably connected to earth reference potential by a resistance equal to or less than a predetermined value. The device commonly takes the form of a grounding clamp (1) for connecting said device to the conductive element, the clamp (1) conveniently taking the form of a pair of spring loaded jaws (2, 3). The clamp (1) incorporates or is connected to a monitoring unit comprising a current-to-voltage converter with a voltage output proportional to the resistance of the conductive element, a comparator which determines at predetermined intervals whether said voltage output is equal to or less than a preset reference, and hence whether the measured resistance is equal to or less than the predetermined value, and signalling means (8) which are actuated to provide an indication as to whether the measured resistance is equal to or less than the predetermined value. The signalling means (8) is most conveniently a light emitting diode.
|
