EN ISO 8503-2-2012 pdf free download.Preparation of steel substrates before application of paints and related products – Surface roughness characteristics of blast – cleaned steel substrates – Part 2: Method for the grading of surface profile of abrasive blast-cleaned steel – Comparator procedure (ISO 8503-2:2012).
This part of ISO 8503 describes a visual and tactile method for assessing the grade of the profile which is produced by one of the abrasive blast-cleaning procedures described in ISO 8504-2. The method uses ISO surface profile comparators for assessing, on site, the roughness of surfaces before the application of paint or other protective treatments.
NOTE Where appropriate. ISO surface profile comparators can be used for assessing the roughness profile of other abrasive blast-cleaned substrates and, in addition, their use is not restricted solely to surfaces that are to be painted.
The method is applicable to steel surfaces which have been blast-cleaned by use of either shot abrasives or grit abrasives, but is only applicable to grades Sa 2Y2 and Sa 3 of ISO 8501-1 where the entire surface under test shows an overall blast-cleaned appearance.
It is applicable to surfaces which have been cleaned with either metallic or non-metallic abrasives.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 8501-1, Preparation of steel substrates before application of paints and related products — Visual assessment of surface cleanliness — Part 1: Rust grades and preparation grades of uncoated steel substrates and of steel substrates after overall removal of previous coatings
ISO 8503-1:2012, Preparation of steel substrates before application of paints and related products — Surface roughness character,slics of blast-cleaned steel substrates — Part 1: Specifications and definitions for ISO surface profile comparators for the assessment of abrasive blast-cleaned surfaces
ISO 8503-3, Preparation of steel substrates before application of paints and related products — Surface roughness characteristics of blast-cleaned steel substrates — Part 3: Method for the calibration of ISO surface profile comparators and for the determination of surface profile — Focusing microscope procedure
ISO 8503-4, Preparation of steel substrates before application of paints and related products — Surface roughness characteristics of blast-cleaned steel substrates — Part 4: Method for the calibration of ISO surface profile comparators and for the determination of surface profile — Stylus instrument procedure
ISO 8504-2, Preparation of steel substrates before application of paints and related products — Surface preparation methods — Part 2: Abrasive blast-cleaning
3 Terms and definitions
For the purposes of this document, the definitions given in ISO 8503-1 apply.
4 Principle
The surface profile of the test surface is compared by visual or tactile means with the profile of each of the segments of a calibrated ISO surface profile comparator to identify the two segments between the profiles of which the test surface lies. The results are converted to the appropriate grading: lne, medium” or coarse”.
5 Apparatus
5.1 ISO surface profile comparator, calibrated, conforming to the requirements of ISO 8503-1 or other comparator design and configuration with four segments that conform to the profiles specified in ISO 8503-1.
NOTE In ISO 8503-1, two comparators are specified: one with surface profiles corresponding to surfaces which have been blast-cleaned using grit abrasives (reference comparator G) and one with surface profiles corresponding to surfaces which have been blast-cleaned using metallic shot abrasives (reference comparator S). The nominal values for these profiles, which identify the limits of the three grades “fin&, “medium and “coarse”, are given in ISO 8503-1.
If a mixture of shot and grit abrasives is used to blast-clean a substrate, the grit-abrasive reference comparator G should preferably be used.
Some abrasives (for example cast steel and cut wire) change their shape during use so that the “new” abrasive gives an angular profile, but a “working miX” gives a rounded profile. Hence, the relevant comparator should be selected for these abrasives (described in ISO 8504-2).
5.2 Hand lens, with magnification not exceeding x7,
6 Maintenance and re-calibration of comparators
Comparators require careful handling. If any wear is detected, the comparator shall be discarded or, if appropriate, re-calibrated (see ISO 8503-1:2012, Clause 7).
Comparators in frequent use should be checked against an unused comparator at three-monthly intervals or whenever the surface appears worn or damaged. If a segment of a used comparator, when compared with the equivalent segment of an unused comparator, yields a different grading assessment (see this part of ISO 8503) of a surface profile, the used comparator should be discarded or re-calibrated.EN ISO 8503-2 pdf download.