VHE‘s enhanced ohmmeter measures the electrical resistance between points of different voltage potential of which conventional ohmmeters do not have this capability.
Much of the equipment installed in aluminium smelter potroom has significant electrical potential to earth (or ground). The series connection of the pot busbar systems means that pots frequently have a potential to earth of 1500 volts dc, and in the the most recent systems this can exceed 2.000 volts dc. Alumina dust and metallic objects can compromise the installed electrical insulation and it is necessary to monitor insulation performance on a regular basis.