What is a Coating Thickness Gauge?

Ever notice how pipelines suddenly collapse due to wear and tear caused by corrosion?

The truth is that the corrosion effect has been gradual over the years and only came to everyone’s attention when it caused the installation to collapse. It must be noted that this kind of failure occurs every day in different industries, especially the ones that employ ferrous materials extensively. Nevertheless, quality inspectors and professionals often use various methods and techniques to avoid this type of failure. One standard way to mitigate against corrosion-induced failure is with the use of Paint Thickness Gauge. This article seeks to answer all the essential questions about coating thickness gauge. If you’re ready, then let’s begin.

1. What is a Coating Thickness Gauge?

Substrate coating is a common way of protecting materials from the negative effect of the environment including oxidation that often leads to material deterioration. The coating material is important in maintaining the integrity of the installation. However, what’s more important is the gauge or thickness of this coating material.

The coating thickness gauge is the device used for ensuring that the coating thickness meets the specific requirements stated in its design for the durability and lifespan of the installation. It is essential to monitor the coating film intently during the wet and dry stage. A wet coating thickness gauge should suffice for the wet stage to avoid coating failures like cracking and flaking resulting from drying too quickly.

2. What are the applications of a Coating Thickness Gauge?

The application of a coating thickness gauge is varied, and its application encompasses several industries. It is suitable for measuring coating thickness on both ferrous and non-ferrous substrates as well as different coating materials including liquid and powder coating materials. For instance, petrochemical, energy, power generation, and oil and gas industries employ different wet coating materials to achieve the specified coating thickness that will guarantee the designed lifespan of a substrate. This thickness often depends on factors that include the environment of the installation, material transported in the pipes, and the designed lifespan. The coating thickness gauge helps the quality inspector to ascertain that this coating meets specified requirements to ensure the integrity of the substrate material over its lifespan.

3. How does a Coating Thickness Gauge work?

There are generally two types of coating thickness gauges, and they are based on the type of substrate under consideration which includes ferrous and non-ferrous substrate. There is a magnetic and an ultrasonic pulse-echo coating thickness gauge. The magnetic coating thickness gauge relies on either a magnetic pull-off technique where the magnetic pull of the metal substrate or an electromagnetic induction of the metal substrate is measured after coating.

The ultrasonic pulse-echo on the other hand sends a sound pulse with high frequencies through non-ferrous materials. The time difference in the travel of the sound pulse through the non-ferrous substrate material is measured to ascertain the coating thickness.

4. How accurate are Coating Thickness Gauges?

Measuring coating thickness can be tricky especially for coatings that are micromillimeters in thickness. Getting the coating thickness right largely depends on the sensitivity and accuracy of the coating thickness gauge. Fortunately, there are coating thickness gauges that are very accurate and can measure the tiniest differences in coating layers. However, the prices for very accurate models are higher than the moderately accurate ones. Additionally, the coating application techniques can make a significant difference in the readings on the coating thickness gauge and the actual coating thickness on certain parts of the substrates. Hence, it is always good practice to ensure that your coating thickness gauges are properly calibrated and experienced operators and coating professionals carry out the operations.


In the end, using the right coating thickness gauge depends on the type of substrate material you wish to measure. Nevertheless, a good understanding of the working principle of these coating thickness gauges can definitely help you choose the right coating thickness gauge. But more importantly, partnering with a dependable and quality conscious brand like NDT-KITS with years of consistent quality coating thickness gauge delivery will reduce your stress significantly. NDT-KITS has one of the most competitive prices in the industry without having to compromise the quality of their products. You can join many other partners who have transitioned from just a customer to an ambassador of NDT-KITS. The ball is now in your court.

Leave a Reply

Your email address will not be published. Required fields are marked *