The Elcometer 129 Rubert & Rugotest Surface Comparators (E129-1, E129-2, E129-3) are reference plates used to assess the surface profile of a blasted metal surface quickly, in the field, without electronic instruments. After abrasive blasting, the achieved profile determines how well a coating will key to the steel. The comparator gives the inspector a fast grade so that work can move from blasting to painting before flash rust sets in, which is also valuable in hazardous areas where electronic equipment is prohibited.

Each comparator carries six reference roughness values, formed on a corrosion resistant metal. Assessment follows ASTM D4417 Method A: the appropriate comparator is held against the cleaned surface and compared, segment by segment, by sight, with or without magnification, or by touch. The closest match indicates the profile grade. Roughness is shown in both classes and roughness averages for easier identification, and all models are supplied in metric.

The range covers different finishes. The E129-1 Rubert Grit and E129-2 Rubert Shot comparators carry section profiles of 0.4, 0.8, 1.6, 3.2, 6.3 and 12.5µm. The E129-3 Rugotest combines shot and grit profiles on a single block at N6 to N11, equivalent to 0.8, 1.6, 3.2, 6.3, 12.5 and 25µm roughness averages. The Elcometer 129 Rubert & Rugotest Surface Comparator can be used in accordance with AS 3894.5. Used in coatings inspection and surface preparation, it is supplied by BAMR, South Africa's authorised distributor.