: A strip of pressure-sensitive tape is pressed onto the prepared steel surface with consistent pressure.

: The captured dust is visually compared against pictorial references to determine its quantity and inspected under magnification to determine its particle size . ISO 8502-3 Dust Level Ratings

Here are the ISO 8502-3 dust level classes:

If you only buy one dust assessment reference, get the ISO 8502-3 chart. Just remember to pair it with salt testing for complete surface cleanliness.

– Indispensable for field dust assessment, but don’t rely on it alone. It answers “how big and how much?” but not “is it chemically harmful?” Use it as a screening tool, not a final verdict for high-stakes coatings.