Fluorescent comparators consist of a number of transparent tokens, measuring typically 30 X 100 mm and a few mm thick having yellow/green fluorescent marks of known dimensions. The various designs offer dots and lines of known dimensions while some provide fluorescent circles to allow an accurate estimate of the spacing and grouping of the indications. The markings on the comparators appear a brilliant yellow/ green when viewed under UV-A of a peak wavelength of 365 nm. Under white light illumination they appear bright green. There are 13 various designs which cover a wide range of applications in magnetic particle inspection, penetrant testing, radiography and visual inspection.
Type 1: A transparent token 17 X 80 mm having 10 dot type indications with diameters from 0.005 to 0.125 inch.
Type 2: A metric equivalent of the Type 1 with the diameters of the dots ranging from 0.2 to 3.0 mm
Type 3: TAM 135273, a transparent token measuring 20 X 100 mm to the requirements of Pratt and Whitney having both open circular and linear indications ranging from 0.010 to 0.18 inch, 0.2 to 4.6 mm, the lengths of the linear indications being the diameters of the circles. (This model has inch measurements as well as the metric ones).
Type 4: General Electric Company FPI Scale, a transparent token measuring 20 X 120 mm having ten each solid circular and linear indications from 0.005 to 0.125 inch, the lines being the diameters of the circles. this Type is manufactured to the requirements of General Electric. (10 indications)
Type 5: Magnetic Particle; a transparent comparator 20 X 100 mm. Having eight linear indications from 0.030 to 0.500 inch.
Type 6: Spacing; this comparator measuring 25 X 120 mm. Is designed to assist in sizing and spacing of indications. Four each different sized filled circles from 0.015 to 0.125 inch diameter are placed in a line at distances of 1,2 and 3 diameters for this purpose. Five open circles having diameters from 0.0625 to 0.5 inch are also supplied.
Type 7: Modified General Electric; this is very similar to the Type 6. Indication sizes 0.015 to 0.045 inch, circles0.03 to 0.50 inch (3indication sizes, 8 circles with linear equivalents
Type 8: Spacing type comparator similar to Type 6 with metric indication sizes 0.30 to 1.5 mm, circles 2.5 to 12.5mm (6 indication sizes 5 circles) diameter from 2.5 to 12.5 mm.
Type 9: This comparator, measuring 20 X 100 mm has ten each circular and linear indications ranging from 1/64 to 1/4 inch in fractions of an inch diameter/ length.
(10 fractional indications)
Type 10: Foundry Circular; this comparator measuring 20 X 100 mm has three open circles 0.093, .0125 and 0.375 inch with linear equivalents.
Type 11: Metric; this comparator measures 20 X 100 mm and has linear indications ranging from 0.7 to 12.7mm (8 indications)
Type 12: Comparator for the Foundry Industry with three filled 0.062, 0.125 and 0.187 inch.
Type 13: Swing Away; this comparator is made like a feeler gauge and has ten individual plastic leaves each with a solid circular indication ranging from 0.005 to 0.125 inch diameter.
Type 13: Swing Away; this comparator is made like a feeler gauge and has ten individual plastic leaves each with a solid circular indication ranging from 0.2 to 3.00 mm diameter.
Type 14: TAM 190466 Swing Away; this comparator is made like a feeler gauge and has ten individual plastic leaves each with a solid circular indication ranging from 0.005 to 0.180 inch diameter.
Comparator layouts shown on the specification page