Principle of measurement for organic coatings

The measurement of organic coatings is more complex than measurement of metallic coatings. To obtain the best measurements for most coatings, a beta backscatter radiation technique is used. This technique uses a radiation source emitting beta particles (high-speed electrons) which are directed at the organic coating. These electrons pass through the coating and hit the metal substrate below the organic layer where they are reflected back through the coating to an ion chamber radiation detector. The intensity of the reflected or backscattered radiation changes with the thickness of the organic coating. To obtain the best measurements, it is necessary to have a system that uses not only organic measurement sensors, but many of the ancillary equipment to accept all these data, control the measurement scanners and generate QC reports. This has been accomplished by developing a single system that has the capability of measuring tow coatings of paint on both sides of the strip, as well as configuration to measure additional coats both wet and dry