Note: Always ensure that the PDF chart you are using clearly displays the pictorial standards for comparison. 5. Summary Table: ISO 8502-3 Evaluation Dust Class Quantity Description Visual Appearance Absolutely clean. 1 Visible only with 10x magnification. 2 Just visible to the naked eye. 3 Clearly visible to the naked eye. 4 Significant dust coverage. 5 Total contamination. Reference: Elcometer 142 Kit Description. Conclusion
Choose a representative area of the blast-cleaned steel. Ensure it is dry and free of condensation.
Large, distinct grains easily spotted without magnification. Particles larger than Massive particulate matter or debris.
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While official ISO standards must be purchased directly from ISO or national bodies, updated PDF summary charts allow field inspectors to quickly reference specifications on tablets and smartphones without carrying bulky paper manuals into confined spaces. iso 85023 dust level chart pdf updated
Always perform a high-pressure air blow-down after blasting. Ensure the compressed air used for blowing down is strictly oil-free and dry (compliant with ASTM D4285).
Low density. Particles are visible to the naked eye but cover a minimal percentage of the surface area.
Compare the tape sample against the ISO 8502-3 reference chart using a magnifying glass to determine the Dust Quantity Rating and Dust Size Class . Understanding the ISO 8502-3 Dust Level Ratings
Large particles between 0.5 mm and 2.5 mm in diameter. Note: Always ensure that the PDF chart you
While quantity impacts adhesion, particle size determines the "smoothness" and integrity of the first coating layer. INTERNATIONAL STANDARD ISO 8502-3
To properly use the dust level chart, you must first collect a representative dust sample. Follow this updated procedure:
Ensure your PDF reference reflects the latest revisions regarding standard backcloth colors. Typically, a black background is used for light-colored dust (garnet, silica, aluminum oxide) and a white background for dark dust (coal slag, steel grit). Best Practices for Passing an ISO 8502-3 Inspection
Always perform a secondary ISO 8502-3 tape test after dust remediation to verify that the surface now meets the contractually mandated threshold. 1 Visible only with 10x magnification
Heavy accumulation. Distinct clusters covering parts of the tape.
Inspectors must also classify the physical size of the dust particles using an illuminated hand lens with 10x magnification. Description Particle Size Dimension Particles not visible Under 50 µm in diameter Class 1 Small particles Visible only under 10x magnification (50 µm to 100 µm) Class 2 Medium particles
Part of a broader series focused on surface cleanliness, ISO 8502-3 uses a to qualitatively assess loose particulate matter. It functions as a rapid "pass/fail" mechanism or a permanent record of surface quality prior to industrial paint application. The evaluation relies on two primary data streams:
. Run the roller three times back and forth over the tape, with each stroke lasting roughly 5 to 6 seconds.
ISO 8502-3 is an international standard titled "Preparation of steel substrates before application of paints and related products — Tests for the assessment of surface cleanliness — Part 3: Assessment of dust on steel surfaces prepared for painting (pressure-sensitive tape method)" .
