Since 1952 Telemagnetica builds fixed and portable equipments for inspecting the integrity of insulating coatings.
The various models are able to control insulating coatings of each type applied to any conductive support: paints, bituminous tapes, polyethylene ribbons or extruded, paint on concrete rebars.

For a simple calibration the Crest Voltmeter mod.188 is available, which allows the visualization on display of the voltage actually applied to the coating.