3.3 Equipment Preparation
3.3.1 Using the drilling die, cut three (3) test samples have a diameter of 16.0+/-0.2 mm, from varying locations on the test material. The test material must have a minimum thickness of 6mm. Test samples must have parallel top and bottom surfaces, and sides which are perpendicular to the top and bottom surfaces (i.e., cylindrical in shape).
3.3.2 If a sample with a thickness of less than 6mm must be used, it should be cut in the manner described above. The test sample must then be bonded to a second piece of rubber which is also cut in the same manner and has a minimum durometer of 65 Shore A. The two pieces must have a combined thickness of at least 6mm. Cyanoacrylate (“super-glue”) is the recommended adhesive.
3.3.3 The equipment is properly calibrated when the “standard elastomer” produces an average weight loss of 200+/-20 mg. If the weight loss is more than 220 mg, the sandpaper is too aggressive and must be adjusted. This can be done by inserting an aluminum disc into the sample holder. Pass the aluminum disc over the sandpaper until testing with the standard elastomer produces a weight loss of 220 mg or less. If the weight loss is less than 180 mg, the sandpaper is not aggressive enough and must be replaced.
3.3.4 If any measurement varies by more than 15 mg from the others, it should be discarded and another measurement should be taken.
3.3.5 Test three (3) samples per material.
3.4 Testing Procedure
3.4.1 Determine the specific gravity (SG) of the test material according to TM-R-033 or VF-A04.
3.4.2 Load the sample holder with the 250 gram and 500 gram weights (bringing the total weight of the sample holder to 1 kg, as the sample holder weighs 250 grams)
3.4.3 Using your fingers, remove any burrs, and then brush any dust or loose particles from the sample with a soft bristle brush.
3.4.4 Weigh the test samples to the nearest 0.001 gram (W₁)