Top Tips To Choose A Film Thickness Gage

thickness gage performance

A film thickness gage is one of the most essential instruments used in the coatings industry today. Errors in film thickness estimates lead to a significant waste of money, material and time. If a coating application makes a dry film excessively thick, this leads to failures such as flaking, cracking or excessive drying time. In the event that a film is excessively thin, its protective capabilities and hiding power become inadequate and time is lost by having to recoat the entire surface. 

For these reasons, it is important you know how to properly select a film thickness gage. Below are some key factors you can consider when choosing a film thickness gage:

Film Thickness Gage Performance

When choosing this type of thickness gage, always keep in mind its level of performance. A good question to ask yourself is how precise or accurate you need it to be. A high performance gage is needed if you are applying less than 1.0 mil of dry paint film. If you want to further improve your accuracy, choose one which has single or a two point calibration feature. Remember, the gage can be calibrated in line with certified film thickness standards. 


Always consider the substrate the coating is being applied to when choosing a thickness gage. Is the substrate metal or non-metal? If it is metallic, the metal is either ferrous, such as steel, or non-ferrous, such as aluminum. It is worth noting that ferrous metals have magnetic properties, unlike their counterparts, the non-ferrous metals. 

ISO Compliance 

You might be required to document your measurements for ISO compliance. In this case, a film thickness gage with computer interface capabilities and memory is your best choice.

Measurement Area

Another important factor to consider when choosing a film thickness gage is the measurement area location. You will need an exterior probe sensor when measuring inside corners, pipes, and very small surfaces. Unfortunately, when external probe sensors come into play, the choice of film thickness gage models becomes quite limited. 

Certified Thickness Standards

It is recommended you get a certified thickness standard to check if the gage is performing as required. 

Bottom Line

Before choosing a film thickness gage, there are some important factors you should have in mind. For effective coating to take place, you need a well measured film thickness gage. 

Willrich Precision Instrument offers a wide range of film thickness gages that can meet all your gaging and inspection needs. We are an ISO certified company and have been the premier provider of precision measurement systems for over four decades. Our staff is knowledgeable and ready to help you with any questions you may have regarding your metrology needs. Feel free to contact us to discover more about the products and services we offer.

by George Chitos