Additional set of special rubber O-rings, per set

Steel dust evaluation equipment and cleaning and CTR testing.
Purpose: Dust on sandblasted steel surfaces can reduce the adhesion of applied coatings and, by absorbing moisture, can promote corrosion of the sandblasted steel.
* Adhesive tape: consists of a self-adhesive, pressure-sensitive, transparent, practically colorless tape, with an adhesion force of at least 190 N/m.
* Handheld lens with 10x magnification capacity.

Procedure:
1.- First discard the first three turns of tape from the roll.
2.- Remove a piece approximately 8" long.
3.- Touching the sticky side only at the ends, press about 6" of newly exposed tape firmly onto the surface to be tested.
4.- Press by placing your thumb on one end of the tape and moving your thumb along the tape at a constant speed and pressure. Do this three times in each direction, making each stroke take approximately 5 to 6 seconds.

• NOTE: While a test procedure in which pressure is applied to a tape with the thumb is subjective, it is generally adequate, especially for use in situations where dust-free surfaces are required. In controversial cases, except when rust grade C or D is involved, pressure can be applied to the back of the adhesive tape with a spring-loaded roller. See ISO F502.

5.- Remove the tape from the test surface.
6.- Display the results on an appropriate contrasting card, tile or background paper by rubbing with your thumb to adhere.
7.- Determine the AMOUNT OF DUST on the tape by visually comparing an area of ​​the tape equal to the reference area shown in FIGURE 1 below.
8.- Determine the predominant DUST PARTICLE SIZE on the tape by referring to TABLE 1, which defines six classes of dust particle size, designated 0, 1, 2, 3, 4 and 5.
9.- Complete a significant number of tests to correctly identify the characteristics of the tested surface. Complete at least three separate tests for each surface of a particular type of appearance. Complete at least two additional tests for each result that has a quantity rating or less.

• NOTE: Please refer to ISO 8502-3 for the exact procedure.