Worldscan

“An instrument that employs ultrasonic sound waves to measure the thickness of steel” (Automotive Steel Partnership, 1991, p. 17). In order for the WorldScan “System” to operate as desired, it must be calibrated to accommodate the external factors which influence the fluorescing phenomenon. All film coatings fluoresce uniquely. Also, the substrates (bases) to which the films are applied affect the ways the film coatings adhere macroscopically to the surfaces of those substrates. Calibrations must film coatings adhere macroscopically to the surfaces of those substrates. Calibrations must be set up for each base and film combination. Produced by CMT, Inc. in Cleveland, OH, is a weight coating analyzer which operates by the ultraviolet fluorescence principal. The WorldScan contains an internal 370 NM ultraviolet lamp source which excites a film coating at this wavelength. The film coating responds to this excitation by emitting energy (called fluorescing). The amount of fluorescing is proportional to the amount of film present; thus the greater the amount of film present, the greater the fluorescence. The WorldScan uses this fluorescing signal to give the end result of a calibrated reading in final engineering units of (mg of coating) / (ft2 of sheet metal). The WorldScan is calibrated by collecting data comprised of the amount of fluorescence of a base and film combination for a given amount of coating per square foot of substrate. Coating weights are typically measured by a laboratory scale. The calibration data are then fit to an equation, which can be programmed into the WorldScan unit. The Control Software for the WorldScan provides the capability to program a linear equation of the form: y = Ax + B which is most common in the typical range of applications. (CMT, Inc., Cleveland, OH)

Source: The OHIO State University