The Elcometer 101 Magnetic Coating Thickness Gauge is a non destructive dry film thickness gauge for measuring coatings on magnetic steel substrates. As the world's first portable coating thickness gauge, with the original produced in 1947, it established the method now standard across coatings inspection. This model is discontinued.

Coating thickness governs both protection and cost: too thin and the substrate is left vulnerable, too thick and material is wasted, so a reliable field measurement informs whether a finish meets specification. The Elcometer 101 reads thickness magnetically without damaging the coating and is insensitive to hot and cold surfaces, which makes it suited to hot sprayed metal coatings. It incorporates a reading hold feature and offers an accuracy of plus or minus 10%. With no electronics required, it is also suited to hazardous areas.

The Elcometer 101 can be used in accordance with AS 2331.1.3, ASTM B 499, ASTM G 12, BS 5411-11, ISO 2178 and SSPC PA2, the recognised standards governing magnetic coating thickness measurement. Some of these have been superseded but remain recognised in certain industries.

Although discontinued, this gauge is documented here by BAMR, South Africa's authorised distributor of Elcometer instruments, which can advise on current equivalents.