Tungsten Disulfide Coating Thickness Measured by Magnetic Thickness Gauge (II)

Coating thickness of tungsten disulfide can be measured by a main type of magnetic thickness gauge, magnetic or electromagnetic induction thickness gauge. Tungsten disulfide coating with diamagnetism is usually applied to protect the metal surfaces.

Magnetic thickness gauge is a common magnetic thickness gauge, which has very high application value in the detection of coating thickness. It is a nondestructive measurement method of using magnetic thickness gauge in the measurement of non-magnetic coatings.

The magnetic thickness gauge mostly uses one of two operating principles: magnetic stretching or magnetic/electromagnetic induction. The thickness of tungsten disulfide coating can be measured by magnetic or electromagnetic induction thickness gauge.

The magnetic induction thickness gauge uses permanent magnet as the magnetic field source, and uses Hall effect generator or magneto-resistor to sense the magnetic flux density at the magnetic pole of the magnet. Electromagnetic induction thickness gauge uses alternating magnetic field. It uses soft ferromagnetic rods with thin coils to produce magnetic field. Another coil is used to detect changes in magnetic flux.

These electronic instruments can effectively measure the flux density changes on the steel surface near the surface of the magnetic probe. And the flux density on the probe surface is directly related to the distance apart from the steel substrate. Therefore, the thickness of tungsten disulfide coating can be successfully measured by observing the magnetic flux density in the process of thickness measurement.

This kind of electromagnetic meter has many shapes and sizes. They usually use constant-voltage probes to provide observable data. And the measured readings will be clearly displayed on liquid crystal displays (LCDs). It can store measurements or analyze readings in real time, and output the results to a printer or computer for further checks. The measurement deviation of this kind of instrument is generally about (+1%). In order to obtain more accurate measurement results, operators should carefully follow the manufacturer's instructions. The test method can refer to international standards such as D7091, ISO 2178 and ISO 2808.

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