Paint meters, also known as coating thickness gauges, are essential tools used in the coatings industry to measure dry film thickness. Measuring dry film thickness is extremely important because it provides crucial information about the expected lifespan of the substrate, the suitability of the product for its intended purpose, its appearance, and compliance with various international standards.
FenderSplendor provides various types of coating thickness gauges that can measure dry film thickness. These gauges are also called paint gauges or mil gauges and they come in both mechanical and digital forms that are suitable for non-destructive or destructive testing. Moreover, they include a diverse range of probes and calibration foils that cater to your specific application needs.
FenderSplendor also manufactures an Industrial Coating Thickness Gauge, commonly called a Mil Gauge, Paint Thickness Tester or Paint Depth Gauge. Using direct distribution has allowed FenderSplendor to offer buyers a $200-$300 savings over competitive gauges.
How Does A Coating Thickness Gauge Work?
You can use a digital coating thickness gauge to measure the dry film thickness on both magnetic and non-magnetic metal surfaces like stainless steel or aluminum. If you want to measure the thickness of non-magnetic coatings on magnetic substrates like steel, you can do so by using the principle of electromagnetic induction. Similarly, for non-conductive coatings on non-ferrous metal substrates, you can use the eddy current principle. FenderSplendor Paint Meters use both methods with their Paint thickness gauges. International standards paint meters should be recognized with, ISO2178 and ISO2361, also DIN, ASTM and BS which FenderSplendor Paint Meters feature.
What Is A Permanent Magnet Thickness Gauge?
To measure the thickness of a coating, a balanced arm with a permanent magnet is used. A helical spring is attached to the arm on one end and to a scale wheel on the other. By turning the scale wheel, the force gradually increases until the magnet detaches from the surface. Instead of force, the scale is marked in thickness units. The pointer on the case of the instrument shows the thickness of the coating.
What Is An Electromagnetic Induction Coating Thickness Gauge?
Electronic coating thickness gauges use the principle of electromagnetic induction to measure thickness on magnetic substrate materials. A probe system with three coils is used. The central coil is powered by the instrument, while the other two coils detect the resulting magnetic field on either side of the central coil. The signal generated by the instrument is sinusoidal, which establishes an alternating magnetic field around the central coil.
When there is no magnetic material nearby, the magnetic field goes through both coils evenly. When the probe gets closer to the uncoated surface, the magnetic field becomes uneven, with more magnetic field going through the closest coil and less going through the farthest coil. This creates a voltage difference between the two coils, which measures the distance to the surface (the thickness of the coating).
How Accurate Are Coating Thickness Gauges?
When choosing a coating thickness gauge, it is important to consider the level of accuracy needed. There are different types of gauges available ranging from moderately accurate to very accurate ones, and the price increases with the level of accuracy. It's also important to note that the variability of the coating thickness on a surface is affected by the coating application process and other factors. The results can also be influenced by the skill and knowledge of the operator using the gauge.
How To Test The Accuracy Of Coating Thickness Gauges
To ensure the accuracy of a gauge, it is crucial to use coating thickness standards that can be traced. Begin by zeroing the gauge on a smooth, uncoated substrate and then set it to a known thickness standard that is close to the maximum thickness. Measure the intermediate thickness standards and compare their readings to the actual thickness of the standard. The differences between the reading values and the standard value are called errors. These errors are best expressed as a percentage of the reading.
During the manufacturing process, coating thickness gauge manufacturers perform calibration to ensure the gauge meets accuracy requirements. This involves setting the gauge to known thickness values and checking intermediate values. Electronic instruments store reference points of key values in the gauge's memory.
If you’re looking to buy a coating thickness gauge, it’s always wise to use a trusted, reliable brand. FenderSplendor has served over 15K+ customers and counting. They have a long track record of producing high quality coating thickness gauges, those are the types of reputable dealers you want to purchase from.
Calibrating A Coating Thickness Gauge
The type of material, shape, and surface finish of the metal substrate being tested will affect the calibration of coating thickness gauges. For instance, steel alloys have varying magnetic properties while different aluminum alloys and non-ferrous metals such as copper, brass, and stainless steel have varying conductivities.
The linearity of a coating thickness gauge may be impacted by certain factors. For instance, if the gauge is set up on mild steel, it will show a different reading for the same thickness of coating on high carbon steel. Additionally, similar linearity issues can arise on thin or curved substrates, as well as on profiled substrates like blast cleaned steel that is commonly used in structural steelworks.