Plating Thickness Gauge | How To Measure Plating Thickness?

Time:2020/04/14 14:24:00 Browse:675

The plating thickness measurement is an important part of the electroplating process quality inspection and an important guarantee for the quality of the electroplating products. In order to control the plating thickness, various measurement methods are needed. The most common of which is the non-destructive measurement of the plating thickness using the magnetic method and the eddy current method plating thickness gauge.

I. Various ways to measure the plating thickness

1. Magnetic induction method plating thickness gauge

The plating thickness is determined by the amount of magnetic flux that the probe passes through the non-ferromagnetic plating and flows into the ferromagnetic metal substrate. Magnetic induction plating thickness gauge is suitable for measuring non-magnetic metal platings on ferromagnetic metals such as steel, paints, varnishes, enamels, plastics, rubber coatings, chromium plating, zinc plating, cadmium plating, copper plating, etc. 

2. Eddy current method plating thickness gauge

An electromagnetic field is generated in the probe coil by the high-frequency AC signal. When the probe is close to the conductor, an eddy current is formed therein. The closer the probe is to the conductive substrate, the greater the eddy current and the reflected impedance capability. This feedback characterizes the distance between the probe and the conductive substrate, that is, the non-conductive plating thickness on the conductive substrate.

3. Other plating thickness measurement methods

In addition to the above-mentioned magnetic and eddy current thickness measurement methods, there are wedge cutting methods, optical methods (such as contour size measurement method, double beam microscope method), electrolytic methods (such as anodic dissolution Coulomb method), metallographic methods, chemical methods (spotting method, dissolution weighing method, chronofluid method), mechanical method such as weighing method, thickness difference measurement method, X-ray fluorescence method, β-ray backscattering method, capacitance method and other plating thickness measurement methods.

The capacitance method is only used when measuring the insulating plating thickness of a thin conductor. X-ray and β-ray methods are also non-contact and non-destructive measurement, the measurement range is small. X-ray method can measure very thin plating, double plating, alloy plating. The β-ray method is suitable for the measurement of platings and platings with atomic number greater than 3.

II. LS225 plating thickness gauge measures the plating thickness

Among the above-mentioned various plating thickness measurement methods, Linshang Technology has invented new type LS225 plating thickness gauge which uses the magnetic induction plating thickness measurement method. We take this plating thickness gauge as an example to introduce in detail how to measure the plating thickness with the plating thickness gauge.

Measuring principle: magnetic induction thickness measurement method
Suitable substrate: ferromagnetic metal
Measuring range: 0-500μm
Resolution: 0.1μm: (0μm-99.9μm); 1μm: (100μm-500μm)
Model: LS225+F500

2. LS225 plating thickness gauge features

  1. With ultra-small probes, it is especially suitable for measurign thin platings on nails, bolts and other small workpieces, as well as various concave and convex surfaces.

  2. upport 1-5 point calibration, the measurement is more accurate.

  3. With data statistics function, it automatically counts the maximum, minimum, average and standard deviation values of the last 9 measured values

  4. The user can choose a special test fixture, which not only makes the measurement more convenient, but also eliminates the measurement error caused by human factors.

  5. Using digital digital oscillation technology and digital probe technology, the measurement data has ultra-high precision and stability.

3. LS225 plating thickness gauge operation

  1. Zero adjustment. Before use, please use the uncoated standard workpiece or the equipped Fe zero adjustment plate to perform zero adjustment.

  2. Calibration. The LS225 plating thickness gauge is equipped with 7 standard films as standard. Users can calibrate 1 to 5 points according to their needs.

  3. Measurement. The plating thickness tester can save up to 9 sets of test data during measurement. It can display the maximum value, minimum value, average value and standard deviation value of 9 data on the screen.

For complete and detailed operation steps, please refer to the user manual of LS225 plating thickness gauge.

III. Plating thickness relevent knowledge

1. Classification according to the plating

The plating usually has two uses, namely: to endow or improve the state of the material surface, or to make the surface structure of the material have a certain function. Therefore, it can be generally divided into decorative, protective or functional platings.

(1) Protective decorative plating

Corrosion, rust, etc. are the biggest threats to product service life, which will not only damage the appearance, but also affect the function of the product. In addition to improving the appearance of the product, the general decorative plating can also play a protective role, such as chemical anti-corrosion and anti-rust, or mechanical anti-wear to reduce friction.

(2) Functional plating

Functional plating mainly refers to those platings that can make the material surface have a special function. Various new functional platings can increase the surface hardness of the material, improve friction, reduce wear, improve electrical conductivity, reduce contact resistance, enhance magnetism, prevent diffusion and penetration, or repair worn parts.

2. Classification according to the electrochemical relationship between the plating and the substrate

According to the electrochemical relationship between the plating and the substrate, the plating can be divided into cathodic plating and anodic plating. The liveliness of the metal is different, which is also an important way to judge the type of plating.

(1) Cathodic plating

The metal substrate of the cathodic plating is more active than the plating. Such a plating usually covers the substrate completely to protect the substrate. Typical ones are copper and nickel plating on steel. Since the cathodic plating only has a certain thickness, it has a protective effect on the substrate. Therefore, the plating thickness and porosity are required. Usually, a plating thickness gauge is used to control the plating thickness.

(2) Anode plating

The plating metal of the anodic plating is more active than the substrate. When the plating layer encounters corrosive substances, the plating layer will corrode first, thereby protecting the substrate from corrosion. Typical examples include zinc plating on steel.