Home>ASTM Standards>ASTM D814-95(R2020) pdf free download

ASTM D814-95(R2020) pdf free download

ASTM D814-95(R2020) pdf free download.Standard Test Method for Rubber Property—Vapor Transmission of Volatile Liquids
4. Apparatus
4.1 The test apparatus shall consist essentially of glass vapor transmission jars (4.2) for each liquid, on which the test specimens are mounted, and a suitable rack for supporting the jars in an inverted position in such a way as to allow free circulation of air over the surface of the specimen. The apparatus shall be kept in a constant temperature cabinet or room at 23 6 2°C (73.4 6 3.6°F). 4.2 Vapor Transmission Jar—A glass jar of approximately 236-cm 3 ( 1 ⁄ 2 -pt) capacity with an opening of 60.3 6 0.4 mm (2.375 6 0.015 in.) in inside diameter and a wall 3.2 mm (0.125 in.) in thickness at the opening, which shall be ground flat without rounded edges to a smooth ground-glass finish at the contact surface. The opening shall be equipped with a metal screw ring clamp holding a smooth-edged, flat, sheet-metal ring 55.6 6 0.4 mm (2.188 6 0.015 in.) in inside diameter and approximately 68.3 mm (2.69 in.) in outside diameter. The ring clamp and ring serve as a clamping device for holding the specimen against the ground-glass-edge of the jar with a circular specimen area 55.6 mm (2.188 in.) in diameter exposed to the air while permitting the screw clamp to be tightened to form a leak-proof seal without subjecting the specimen to torsional strain. When testing extensible materials, a circular disk of 16 to 20-mesh screen shall be placed inside the screw ring clamp between it and the flat metal ring to prevent stretching of the specimen during the test. The screen disk may be soldered in place on top of the sheet metal ring if desired. N OTE 1—A suitable vapor transmission jar may be prepared from a 1 ⁄ 2 -pt Mason jar equipped with a Kerr-type screw cap, provided the edge of the jar is properly ground and finished with fine emery and the cap is cut with smooth, flattened edges to form the required circular opening. 4.3 Dial Micrometer—The dial micrometer shall conform to the requirements of Method A of Practice D3767. 4.4 Balance—The balance shall be of suitable capacity capable of weighing to 0.005 g.
5. Test Specimen
5.1 The test specimens shall consist of circular disks 68 mm (2.69 in.) in diameter, cut with a sharp-edged die from a sheet of the material being tested. The thickness of the sheet, which shall not exceed 3.2 mm (0.125 in.), shall be measured using the dial micrometer described in 4.3. 5.2 For evaluating the vapor transmission of a particular liquid with respect to a given rubber, three specimens having the same nominal thickness within a tolerance of 63 % shall be tested. The vapor transmission ofthe liquid shall be taken as the average of the values obtained from the two rubber specimens giving the lowest results, providing these check within 620 % of the average so determined.
6. Procedure
6.1 With the vapor transmission jar in an upright position, place 200 cm 3 of the test liquid in it, after which fit the test specimen over the mouth of the jar, place the ring and wire screen in position, and screw down the screw ring clamp lightly. Hold the assembly in the constant temperature cabinet or room at 23 6 2°C (73.4 6 3.6°F) with the test disk lightly in place until temperature equilibrium is obtained. Then screw down the ring tightly and allow the assembly to stand in an upright position for 2 h. Make a tare assembly using a duplicate jar and a test specimen of the same size but without the addition of the test liquid. Place suitable weighting material such as lead shot in the tare jar to bring its mass to approxi- mately that of the assembled jar and contents. Condition the tare jar at the test temperature, seal it, and handle throughout the test in a manner similar to that used for the test jar. Place the test jar on a balance of suitable capacity capable of weighing to 0.005 g, and counterbalance it against the tare jar, adding weights as required for equilibrium. Take the original mass of the test assembly as that of the tare corrected for the added weights and record to the nearest 0.005 g.

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