Introduction and selection of coating thickness gauge

The galvanized coating thickness gauge can non-destructively measure the thickness of non-magnetic coatings on magnetic metal substrates (such as steel, iron, alloys and hard magnetic steel) (such as aluminum, chromium, copper, tantalum, rubber, paint, etc.) and non-magnetic .The thickness of a non-conductive coating on a metal substrate (such as copper, aluminum, zinc, tin, etc.) (eg, tantalum, rubber, paint, plastic, etc.). The coating thickness gauge has the characteristics of small measurement error, high reliability, good stability and easy operation. It is an indispensable instrument for controlling and ensuring product quality. It is widely used in the manufacturing, metal processing, chemical industry, Inspection areas such as commodity inspection.

The iron-based/non-ferrous-based coating thickness gauge uses a magnetic sensor to measure non-ferromagnetic coatings and coatings on ferromagnetic metal substrates such as steel and iron. Coating thickness gauges generally have the following five types according to the measurement principle:

Magnetic thickness measurement

It is applicable to the measurement of the thickness of the non-magnetic permeability layer on the magnetic conductive material. The magnetic conductive material is generally steel\iron\silver\nickel. This method has high measurement accuracy.

Eddy current thickness measurement
Suitable for measuring the thickness of non-conductive layers on conductive metals. This method is less accurate than magnetic thickness measurement.

Ultrasonic thickness measurement

At present, there is no such method for measuring the thickness of the coating layer. Some foreign manufacturers have such an instrument, and the measurement of the thickness of the multi-layer coating layer is not the case where the above two methods cannot be measured. However, the price is generally expensive and the measurement accuracy is high. 

Electrolytic thickness measurement

This method is different from the above three types, it does not belong to non-destructive testing, and needs to destroy the coating layer. The general precision is not high. It is more troublesome to measure radiation thickness measurement.
This kind of instrument is very expensive (generally above 100,000 RMB), suitable for some special occasions.

2 selection:

Dual use:

The instrument is produced and combines the functions of a magnetic thickness gauge and an eddy current thickness gauge to measure the thickness of the coating on iron and non-ferrous metal substrates. Such as:

* Coating thickness of copper, chromium, zinc, etc. on steel or paint, paint, enamel, etc.
* Thickness of anodized film on aluminum and magnesium materials.
* Coating thickness on non-ferrous metal materials such as copper, aluminum, magnesium and zinc.
* Thickness of foil, aluminum, copper, gold and other foil strips and paper and plastic film.
* Thickness of the thermal spray coating on various steel and non-ferrous metal materials.
The instrument complies with the standards GB/T4956 and GB/T4957 and can be used for production inspection, acceptance inspection and quality supervision.

*Using a dual-function built-in probe to automatically identify iron-based or non-ferrous matrix materials, and select the appropriate measurement method for accurate measurement.
* Ergonomically dual display structure for reading measurement data at any measurement location.
* It is easy to operate with the menu selection function of the mobile phone menu.
* The upper and lower limits can be set. When the measurement result exceeds or meets the upper and lower limits, the instrument will give a corresponding sound or flashing light.
* High stability, usually long-term use without correction.

Standard configuration
Conventional type

Coatings for the surface protection and decoration of materials, such as coatings, overlays, chemically formed films, etc., are referred to as coatings in relevant and international standards.

The coating thickness measurement methods are wedge cutting method, light intercept method, electrolysis method, thickness difference measurement method, weighing method, X-ray fluorescence method, β-ray backscattering method, capacitance method, magnetic measurement method and eddy current measurement. The first five of these methods are lossy detection, and the measurement methods are cumbersome and slow, and are more suitable for sampling inspection.

The X-ray and beta-ray methods are non-contact non-destructive measurements, but the device is complicated and expensive, and the measurement range is small. Users must comply with radiation protection regulations due to radioactive sources. The X-ray method can measure extremely thin plating, double plating, and alloy plating. The beta ray method is suitable for coatings with coatings and substrates with an atomic number greater . The capacitance method is only used when thickness measurement is applied to the insulating coating of a thin conductor.

With the advancement of technology, especially after the introduction of microcomputer technology in recent years, the thickness gauges using magnetic method and eddy current method have taken a step toward micro, intelligent, multifunctional, high-precision and practical. The resolution of the measurement has reached 0.1 micron, and the precision can reach 1%, which has been greatly improved. It has a wide range of applications, wide measuring range, easy operation and low cost. It is a wide range of thickness measuring instruments used in industry and scientific research.