What Is Coating Thickness Measurement?
Protective coatings are the primary corrosion barrier for the majority of industrial assets — and
their performance is directly linked to the thickness of the applied dry film. Too thin, and the
coating provides insufficient barrier protection. Too thick, and it may crack, delaminate, or fail to
cure correctly — equally compromising long-term performance. Coating thickness
measurement verifies that the applied coating meets the specified dry film thickness (DFT)
requirements at every stage of the coating application process.
Measurement Methods We Use:
Magnetic Pull-Off (for ferrous substrates) A permanent magnet or electromagnet is held
against the coated ferrous substrate — the force required to pull the magnet away from the
surface is proportional to the coating thickness. Simple, robust instruments suitable for rapid
f
ield screening on steel structures and equipment.
Eddy Current Method (for non-ferrous substrates) Eddy current-based DFT gauges measure
coating thickness on non-ferrous metallic substrates (aluminium, copper, stainless steel) —
where the magnetic pull-off method is not applicable. The same instrument type is used for non
conductive coatings on non-magnetic conductive metals.
Combination Gauges (Ferrous and Non-Ferrous) Modern digital DFT gauges typically
incorporate both magnetic and eddy current measurement modes — enabling measurement on
ferrous and non-ferrous substrates with a single instrument, and providing digital readout,
statistical analysis, and data logging capability.