Measuring Dry Film Thickness on Blasted Substrates

Dry film thickness is arguably the single most important measurement made during the inspection of protective coatings because of its impact on the coating process, quality and cost. Dry film thickness measurements can be used to evaluate a coating’s expected life, the product’s appearance and performance, and ensure compliance with a host of International Standards.


When steel surfaces are cleaned using an abrasive blast cleaning process, the surface is left with a profile. Creating an acceptable level of surface profile increases the surface area and provides an anchor pattern for the coating to adhere to, leading to optimised coating performance and efficient material usage.


Coating thickness gauges are set up and calibrated during the manufacturing process using a smooth metal surface. Smooth metal surfaces are easier to characterise and reproduce than a textured or profiled surface. A gauge set up to measure known thicknesses on a smooth steel surface will show an error when used to measure the same thickness on a profiled surface, such as one achieved by blast cleaning.


The Elcometer 456 IPC

The Elcometer 456 Industrial Protective Coating Thickness Gauge provides a new method for accurately measuring dry film thickness on shot or grit blasted ferrous (steel) substrates; such as ships, pipelines or storage tanks. Designed to significantly reduce inspection times, the Elcometer 456 IPC is incredibly fast and can be used on flat or curved surfaces, taking over 70 readings per minute, in either microns or mils.


With its rugged, hand-held design, ideal for use in the field; the Elcometer 456 IPC has a built-in integral probe for stable, repeatable readings. Users are able to store 150,000 readings in up to 2,500 batches and thanks to its easy-to-use menu structure in multiple languages, the gauge requires minimal training to get started.


Working towards International Standards

With a measurement range of 0 - 1,500μm, each gauge is pre-calibrated with four surface profile ranges, in accordance to ISO 19840. The user selects the appropriate blast profile from the menu; smooth, fine, medium or course, and the gauge automatically calibrates, enabling the user to effortlessly measure a blasted surface. The gauge can also work in accordance with US Navy NSI 009-32 in the same way, when the measurement units are set to mils.

A recent 12 month study by the National Shipbuilding Research Program found that by using a pre-calibrated Elcometer 456 IPC, they were able to measure coatings in half the time of the current dry film thickness measurement method, whilst still maintaining accuracy.


Also working in accordance with SSPC-PA2, the coating thickness gauge takes readings in groups of three to the nearest 10μm (1 mil). When the third reading is taken, the average (mean, xbar) of the three readings is displayed on the right hand side, with the three individual readings on the left; ideal for taking spot measurements and significantly reducing inspection times.


For a step-by-step guide on how to use the Elcometer 456 IPC in accordance with NSI 009-32 and SSPC-PA2, click here.


Users are also able to verify the accuracy of the gauge calibration at any time by selecting Test Calibration and following the simple on-screen instructions.


Instant Live Readings Direct to your PC, Tablet or Smart Phone

As well as reducing inspection times, the Elcometer 456 IPC can also speed up inspection reporting. When out in the field or on site, users can instantly review their data using Elcometer’s free data management software, ElcoMaster®.


Each live reading can be transferred via Bluetooth® to a PC, smart phone or tablet and at the click of a button users are able to generate professional reports. The reports can then be emailed to clients, just seconds after the inspection has been carried out, or uploaded via cloud technology, making it accessible anywhere in the world.


For more information on the Elcometer 456 IPC, click here.