What is the Coating Thickness Gauge? And why is it required?
The Coating Thickness Gauge is a common equipment that is used in the Paint and Finishing Industry to check the thickness of the coating.
Corrosion Protection has become an essential product quality requirement in recent years. Manufacturing companies and users are more aware that their products will be damaged if they do not provide sufficient corrosion protection. Modern Technologies on surface treatment, i.e., painting with organic coatings or by protection through metallic coatings, ensure longer life and use of the product.Â
Thus, due to these factors it has become extremely important to use a coating thickness gauge to check paint thickness. A Coating Thickness Gauge enables a quick assessment of the quality of the paint finish and verifies that the desired thickness is attained.Â
What are the basic principles behind the operation of a Coating Thickness Gauge?
There are two basic methods: The Magnetic Induction and the Eddy Current.
Magnetic Induction / Electromagnetic induction:
Magnetic Induction is the property by which an ordinary piece of iron acquires magnetic properties temporarily due to the presence of another magnet close to it. When using a ‘Fe’ (Iron) base metal, a sensor is placed onto the coated metal object, then the measuring signal changes as a function of the distance between sensor and the substrate (Base Metal). The distance equals the coating thickness or thickness of the coat.
Eddy Current:
Eddy Current Method is based on the principle of generating circular electrical currents in a conductive material. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic fields. In this method, a non-
ferrous (NFe) base metal is used. When the probe is brought near the metal i.e., conductive surface, the coil with the probe generates an alternating magnetic field that sets up eddy currents on the metal surface and hence measures the thickness of the coating.Â
There are coating thickness gauges which operates on both magnetic and Eddy Current principle into one unit. These Coating Thickness Gauges switch automatically from one principle of operation to the other depending upon the substrate.
What Industries would benefit with the usage of a Coating Thickness Gauge?
- Automobile Industries
- Aerospace Industries
- NDT labs
- Â Paint ManufacturersÂ
- Construction
- And many more
 The technology in using a Coating Thickness Gauge has evolved tremendously in the recent years, it can be connected to mobile phones using Bluetooth, wireless sensors or mobile apps. Readings can be automatically recorded hence it reduces typographical error and saves time.
Bombay Tools Supplying Agency Private Limited offers a variety of Coating Thickness Gauges, but their flagship product is the Jafuji Coating Thickness Gauge AC-112 AS. Â
This Gauge is capable of measuring using the Magnetic Induction as well as the Eddy Current principle. The instrument has a measuring Range of 0 – 1250 microns, and the probe is
automatically able to detect whether the base is ferrous or non-ferrous thereby eliminating any scope of error. This instrument is extremely simple to use and is supplied with a zero plate of both Steel and Aluminium material so that we can set zero to check the instrument’s operation. There are also measuring foils of various sizes available which can be used to check the instrument.
This video can easily demonstrate how the Coating Thickness Gauge can be used