Surface Profile Portable Comparator Kit
Article No. 13157
Surface Profile Comparator Kit All Discs
Surface Profile Comparator Kit
Grit, Sand, Shot Reference Discs
Features
- The Keane Tator Surface Profile Comparator is a field instrument designed to quickly and accurately determine the surface profile of blast cleaned surfaces.
- This method is ideal for providing a very quick evaluation of the surface preparation.
- The comparators are available for grit blast, shot blast or sand blast, and comparisons can be made visually or by touch.
- Compact, portable, and has extremely durable reference discs for surface profile determinations.
- A comparator unit consists of a reference disc, a 5-X illuminated magnifier with magnetic disc holder and a plastic disc case.
- A different disc is available for use on sand, shot or grit blast cleaned surfaces.
- Blast cleaned surface is compared with the reference disc through illuminated magnifier.
- Reference Discs are a high purity nickel reference disc comprised of five segments with nominal anchor patterns of 1.5, 2.0, 3.0, 4.5 and 5.5 mils. (One mil = 25.4 microns.) The reference disc is an electroformed copy of a master disc, duplicated to a maximum tolerance of ±.05 mils. The master disc segments were selected from carbon steel plates blast cleaned with a variety of metallic grit operating mixes (G 14 to G 80) at different distances and angles from the source. Segments of the master disc and the electroform copy were measured in the Steel Structures Painting Council Laboratory at the Mellon Institute of Carnegie Mellon University, Pittsburgh, Pennsylvania.
- Anchor Pattern Measurement - The profile was obtained by focusing a calibrated optical microscope first on the highest peak and then the lowest valley in the field of view, noting the movement distance were made at 250X (18 mil field diameter) and 100X (45 mil field diameter). Measurements at higher magnifications are preferred when “fine” profiles are being measured because of greater precision due to lesser depth of field. Measurement of “coarse” profiles is done at lower magnification to include more peaks. Because of the larger field of view at 100X, the statistical probability of a larger peak being measured at 100X versus 250X is slightly greater than six times. Information regarding the “average maximum profile” (h max) of each segment of the reference disc is provided in the accompanying graphs. Reference: J.D. Keane, J.A. Bruno, Raymond E.F. Weaver; SURFACE PROFILE FOR ANTI-CORROSION PAINTS; October 25, 1976 by Steel Structures Painting Council.
Procedure
Determine the profile of metallic grit blast cleaned steel by choosing the reference disc segment that most closely approaches the roughness of the blast. Note that roughness may lie between two segments and be designated, for example 2.5 G/S 76.
- Visual Reference Without Magnification - Hold the disc directly against the surface and make visual comparisons.
- Visual Reference With Magnification - Attach the disc to the magnetic ring on the bottom of the magnifier and hold the entire unit directly on the surface. Either center the disc and make evaluations through the hole or offset it slightly and compare the steel in the “V” notches separating segments. The magnifier can be used with its internal light source or by shining an external light through the slot in the magnifier head. This method may highlight peaks and make comparisons easier.
- Tactile Reference - Compare the roughness of the blast and the reference disc segments using a soft wooden stylus or fingertip.
Delivery Content
Three reference discs in case, Directions for use, Special magnetic illuminated magnifier
Accessories