Coating Thickness Gauge

I. How to Choose the Right Coating Thickness Gauge?

The choice of the most suitable method for measuring paint or coating thickness depends on several factors, including the type of coating, substrate material, coating thickness range, size and shape of the part, and equipment cost.

Coating Thickness Gauge Model Comparison

Coating Thickness Gauge: The Ultimate Guide to Paint & Plating Thickness Measurement

1. Built-in sensor or an external sensor probe?

• The LS220H portable coating thickness gauge has integrated probe, which can be operated with one hand. The operation is relatively simple. Lightweight and portable design for on-site measurements.

• The LS221 and LS225 coating thickness gauges have external probes. The probes of these three coating thickness gauges are connected to the host through a line. The probe is very small and can be placed in a narrow space or used when the measured position is higher or lower. We can use another hand to hold the gauge, so we can easily read the data.

2. Ultra-small size or irregular shaped workpiece?

• If you want to measure a metal material with a special shape or a small size and a large arc, please choose the LS225 coating thickness gauge. LS225 plating thickness tester has two probes: F500 and N1500.

  LS225+F500 plating thickness tester is used to measure the coating thickness on ferrous metal substrates. Its coating thickness measuring range is 0.0-500μm.

  LS225+N1500 plating thickness tester is used to measure the coating thickness on non-ferrous metal substrates. Its coating thickness measuring range is 0.0-1500μm.

• If the diameter of the material you measure is greater than 25 mm and there is no obvious arc, please choose LS220H and LS221 coating thickness gauges.

The Linshang coating thickness gauge meets ISO and ASTM compliance, making it the best coating thickness gauge for industrial applications.

3. Large thickness, ordinary coating, or ultra-thin plating?

• For ultra-thin plating layer measurement (<20μm): Please choose the LS225 plating thickness gauge with the F500 probe.

• For precise measurement of ultra-thin anodized layers on aluminum substrates, we recommend using the LS225 Eddy Current Thickness Gauge paired with the N1500 probe.

• For coating thickness measurement within 5000μm (5mm): Please choose the LS220H or LS221 coating thickness gauge.

II. Digital Coating Thickness Gauge Applications (Non Destructive Testing)

Coating thickness gauges are widely used across various industries to ensure coating quality, durability, and compliance with standards. Below are some key application areas:

1. Coating thickness gauges used in surface treatment industry

Thickness of anti-corrosion, fire-proof, anti-corrosion, anti-wear, thermal insulation coatings and other materials can be measured by coating thickness gauge, such as paint, coating, ink, anodized layer, electroplated layer, thermal spray coating, etc. Different models of Linshang coating thickness gauges are used in different industries. Some of the examples are listed below:

Linshang coating thickness gauge measure different materials

2. Thickness testing of other materials based on metal

Materials such as film, glass, plastic, rubber, ceramics, enamel can be measured by Linshang coating thickness gauge. (perform zero adjustment with provided zero adjustment plates and test thickness of other non-magnetic metal materials).

3. Automotive paint meters in car industry

The car surface paint thickness is measured by an automotive paint meter to determine whether the car has been repainted, sheet metal or other repairs. The car is evaluated based on this. The repair position of the used car can be quickly found by using automotive paint meter. Place the car paint meter vertically on the car paint surface, the paint thickness of this position is displayed on the screen immediately. With scientific measured data, the condition of the used car is more intuitive. Linshang provides a thickness gauge specifically for automotive paint inspection. For more information, please refer to Automotive paint meter-car paint thickness gauge-Linshang

Automotive paint meter

III. FAQs

1. What is the measuring principle of coating thickness gauge? What do "Fe" and "NFe" stand for?

• Linshang coating thickness gauge (except LS225 plating thickness gauge) adopts magnetic induction and eddy current principle.

• The coating thickness gauge can automatically recognize "Fe (ferrous)" and "NFe (non- ferrous)" two different metal substrates. It is recommended to use the "Fe (ferrous)" mode for measuring magnetic metal substrates (such as steel, iron) and the "NFe (non- ferrous)" mode for measuring non-magnetic metal substrates (such as aluminum, copper). For the substrate type, you can also select the "Auto" mode. The coating thickness gauge can automatically recognize the substrate type and switch the measurement mode.

2. What is the response speed of Linshang coating thickness gauge?

Linshang coating thickness gauge response speed is very fast compared with other coating thickness gauges on the market. It uses a highly sensitive probe, measurement can be completed in 0.5s.

3. What are "mil" and "μm"? How to convert the coating thickness gauge unit?

• The terms "mil" and "micron" are units of thickness measurement.

• In the English system, 1 mil = 0.001 inch

• In the metric system, "1 μm" means a micron, 1 μm = 0.001 mm

• To convert Mils to Microns: 1 mil = 25.4 μm

4. How to calibrate coating thickness gauge?

• Select an uncoated workpiece as the calibration substrate; it must be made of the same material as the workpiece to be tested.

• Press and hold the probe firmly against the substrate, then press the button.

• Follow the prompt to lift the probe; the calibration will be successful once completed.

• Recalibrate the device whenever switching to different materials, testing environments (e.g., temperature, humidity), or other conditions.

IV. What is a Coating Thickness Gauge?

Linshang coating thickness gauge can measure non-magnetic coatings on various magnetic metal substrates (such as steel, iron, etc.) and non-conductive coatings on non-magnetic metal substrates (such as aluminum, copper, zinc, etc.) . Coating thickness, paint thickness, or dry film thickness (DFT) is an important variable that affect product quality, process control, and cost control. We offer a range of coating thickness gauges tailored to different industries. If you're looking for the most suitable product for your specific industry, we’re here to help.

See below for more information about coating thickness measurement.

V. How Does a Coating Thickness Gauge Work?

The most common measurement principles include electromagnetic induction and eddy current, while ultrasonic and beta backscatter methods are also used for specific applications.

Some coating thickness testers utilize the electromagnetic induction. This method is used to measure non-magnetic coatings (such as paint, plastic, and zinc plating) on ferromagnetic substrates (such as steel and iron). The probe contains a permanent magnet or an electromagnetic coil, which generates a magnetic field. When the probe approaches a ferromagnetic substrate, the magnetic flux density at the probe changes, with the amount of flux being inversely proportional to the distance between the probe and the substrate.

Other paint thickness gauges operate on the principle of eddy current. It is used to measure non-conductive coatings (such as oxide layers, paint, and plastic) on non-ferromagnetic metal substrates (such as aluminum, copper, and stainless steel). The probe contains a coil that is energized with an alternating current, generating a high-frequency magnetic field. When the probe approaches a conductive substrate, it induces eddy currents within the material. The strength of these eddy currents is inversely proportional to the distance between the probe and the substrate.

Coating thickness gauge principle

Linshang coating thickness tester is dual use device that use both eddy current and magnetic measuring principle. With this state of the art coating thickness gage, you can easily detect the thickness of nonmagnetic coating on a magnetic substrate (ferrous) or an insulating coating on a non-magnetic conductive substrate (non-ferrous) utilizing our auto-detect, integrated probe.

VI. Why Dry Film Thickness Measurement is Important?

Using a Coating Thickness Gauge for regular dry film thickness (DFT) measurement is crucial, as it directly affects opacity, appearance, and protective performance. Proper thickness guarantees protection against corrosion, UV degradation, and wear, preventing premature failures or adhesion issues. Applying too much coating can also be detrimental that can lead to excessive drying time, cracking, and flaking of the paint film. Coating thickness measurement will monitor the paint process and maintain the appropriate coating properties. Many industries, including automotive, aerospace, and marine, adhere to strict ASTM and ISO standards, making accurate measurement essential for compliance. Additionally, optimizing coating thickness helps reduce material waste and production costs while maintaining aesthetic and functional properties, such as uniform surface finish and adhesion. In both manufacturing and maintenance, using a dry film thickness gauge ensures consistent quality control, extends the lifespan of coated surfaces, and enhances overall performance.

VII. How to Use a Digital Paint Thickness Tester?

Before test, you'd better use calibration standards or zero-calibration on an uncoated substrate to ensure measurement accuracy. Then you can follow these steps below:

1. Ensure the test surface is clean, dry, and free from dust, oil, or debris.

2. Turn on the paint thickness tester and select the appropriate measurement mode (Fe, NFe, Fe/NFe) based on the substrate material.

3. Place the probe perpendicular to the coated surface and apply gentle pressure to ensure full contact.

4. The result will be displayed on the screen.

All Linshang Coating Thickness Gauges comply with ISO 2178, ISO 2360, ASTM D7091 and ASTM B499 standards.