Contactless electrical conductivity metering - uses magnetic field line to penetrate conductive layer in spaced regions and in opposite direction

摘要

Electrical conductivity meter has a magnetic field produced by an oscillating circuit inductance whose lines of force penetrate the coating. The lines of force penetrate the coating (5) in opposite directions (B, C) in two separate areas (14, 16). A reduction in the oscillation amplitude produced by the eddy currents in the coating is used as a measure of the electrical conductivity. The areas of penetration of the lines of force through the coating are in the form of concentric circles. The meter is non-contacting, thus avoiding damage to the coating and errors due to contact resistances.