A precision Nickel Comparator Plate that conforms to International Standard ISO 8503 and ASTM D4417 for grit and shot blasted surface roughness comparison. The SRC-340 (Grit) and SRC-341 (Shot) Surface Roughness Comparators can be used to assess the roughness of the surface of a substrate which has been blasted with shot or grit. The classification of blast cleaned surfaces is subjective. In order to assist regular and consistent classification shot blasted surfaces can be defined as angular (after blasting with grit), or dimpled (after blasting with shot), and furthermore into three grades: Fine, Medium, Course (as per ISO 8503).
The grades are defined as follows: Fine : profile equal to segment one and up to but excluding segment two. Medium : profile equal to segment two and up to but excluding segment three. Course : profile equal to segment three and up to but excluding segment four.
The relevant Comparator can be placed against the blasted surface and each of the four sections compared with the surface finish assisted with the use of an illuminated magnifier.
Complies with International Standards: ISO, 8503-1, ISO 8503-2, ASTM D 4417-AABS 772.
