Film thickness, coating and clad layer measurement

Film thickness, coating and clad layer measurement
Thickness gauges, also known as high precision ultrasonic thickness gauge, coating thickness gauges, cladding thickness gauges, paint film thickness gauges, film thickness gauges, etc., can be regarded as the basic measuring instruments used in the coatings industry.

Film thickness

It is generally believed that the relationship between the dry film and the wet film of most coatings.

A false estimate of the thickness of the coating will result in unnecessary waste of time, materials and money. If the film is too thin, its hiding power and protective properties may be insufficient and it will waste time in repainting. If the coating process results in an excessively thick dry film, defects such as cracking, peeling, and excessive baking time may occur, and too thick a coating film may increase the cost.

Wet film

In order to control the variation of the coating film on the surface, it is generally desirable to carry out the thickness measurement when the coating is still in the case of a wet film. The wet film measuring device depends on the shape of the measuring surface area and the measuring range. In addition, wet film measurements are useful when the dry film thickness is only measurable if it is destroyed.

Dry film thickness

Accurate digital ultrasonic thickness gauge provide high quality and reduce material consumption. Dry film measurement enables damage-free measurements and damage measurements for multiple coatings.

No damage measurement

Thickness gauges, also known as coating thickness gauges, coating thickness gauges, cladding thickness gauges, paint film thickness gauges, film thickness gauges, etc., can be regarded as the basic measuring instruments used in the coatings industry. Using electronic digital display measurements, the thickness of the insulating coating on a non-magnetic metal (eg, aluminum) substrate or the thickness of a non-magnetically conductive coating on a magnetically permeable substrate can be measured. These two measurements use different measurement 

principles:

------Use electromagnetic principle on iron base material
------Use non-electromagnetic principle on non-ferrous substrate (eddy current principle)
-----Insulation and non-magnetic coatings include: paint, plastic, glaze, chrome, copper, zinc, powder coating, electroplating, galvanizing, rubber, hard chrome metal spraying, ceramics
----- Non-ferrous base materials include: aluminum, copper, brass, magnesium, stainless steel, zinc
-----Iron base includes: steel, cast iron

Measurement technology

Electromagnetic induction

The method uses two magnetic coil tests, which change the magnetic field of the coil if it is placed close to the ferrous magnetic substrate. The change in the magnetic field is related to the distance between the probe and the substrate. This principle is used to measure the film thickness. That is, the magnetic current is attracted by one of the two coils, and the thickness of the paint film is measured by the change in the magnetic flux between the two magnetic poles. In addition, electromagnetic induction uses a magnetic field driven by a magnet coil to fuse a high-precision semiconductor into a modern iron-based probe.

Eddy current measurement

This method of wet film ultrasonic thickness gauge is employed when measuring a non-conductive coating (NFe) on a non-magnetic substrate (NFe), such as an aluminum substrate. The eddy current measurement method is based on the principle of electromagnetic conduction technology. A small electrical coil that conducts high-amplitude alternating current produces a magnetic field that changes the direction of the magnetic field depending on the direction of the alternating current it is connected to. An eddy current is generated when the Nfe probe approaches the conductive substrate, and the eddy current affects the magnetic field of the coil. the thickness of the paint film depends on the properties of the substrate and the distance between the probe and the substrate.