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ASTM C777-2019 pdf free download

ASTM C777-2019 pdf free download.Standard Test Method for Sulfide Resistance of Ceramic Decorations on Glass
1. Scope
1.1 This test method covers the qualitative determination of the sulfide resistance of ceramic decorations on glass to assure the necessary durability of the decoration. 1.2 This test method provides an indication of performance when and if the decorations are exposed to sulfide attack. 1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. 1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appro- priate safety, health, and environmental practices and deter- mine the applicability ofregulatory limitations prior to use. 1.5 This test method generates hydrogen sulfide gas which is highly poisonous. 1.6 This international standard was developed in accor- dance with internationally recognized principles on standard- ization established in the Decision on Principles for the Development of International Standards, Guides and Recom- mendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
3. Summary of Test Method
3.1 One half of the specimens are immersed in a volume 4 % acetic acid solution that contains 1 mL ofsaturated sodium sulfide solution per each 100 mL of the acetic acid solution in a suitable covered container at room temperature. The degree of attack is determined by visual observation and physical testing of the specimen exposed to a hydrogen sulfide atmo- sphere.
4. Apparatus
4.1 Suitable Covered Container. 4.2 Stirrer. 4.3 Hot Plate. 4.4 Pipet. 4.5 Fume Hood, or other means of adequately exhausting H 2 S produced during the test.
5. Reagents
5.1 Sodium Sulfide (Na 2 S·9H 2 O), reagent grade. 5.2 Acetic Acid (CH 3 COOH, min 99.8 %), reagent grade.
6. Test Specimen
6.1 The decorated ware should be representative of the lot, or run, and should be taken in accordance with the principles stated in Practice C224. 6.2 Standard reference ware of known resistance must be run with each test.
7. Preparation of Test Solution
7.1 Make a 4 % volume acetic acid solution by adding to each 96 mL of distilled water 4 mL of acetic acid. 7.2 Dissolve an excess amount of sodium sulfide in warm (35 to 40°C) distilled water. Make sure there is undissolved sodium sulfide left over. Cool to room temperature. 7.3 Stir into each 100 mL of the 4 % acetic acid solution 1 mL of saturated, clear, sodium sulfide solution for 2 or 3 min. A milk of sulfur will precipitate.
8. Procedure
8.1 Place the test specimens and the reference standard of known resistance into the test solution prepared according to 7.3 at room temperature so that only half of the decoration is immersed. Stir and cover. 8.2 Remove specimens from solution after 15 min and allow to air dry.8.3 Note the degree of attack after 15 min by visual observation and grade. 8.4 Retain a duplicate piece of ware of each decoration under test without exposure as an aid in judging the degree of attack on the specimens under test.
9. Interpretation of Results
9.1 Visual Inspection: 9.1.1 Grade the decoration on the test specimen and refer- ence standard in accordance with one of the following visual test grades: 9.1.2 Visual Evaluation: Grade V1—No attack apparent. Grade V2—Appearance ofiridescence or visible stain on the exposed surface when viewed at a 45° angle but not apparent at angles less than 30°. Grade V3—A definite stain which does not blur reflected images and is visible at angles less than 30°. Grade V4—Definite stain with a gross color change or strongly iridescent surface visible at angles less than 30° and which may blur reflected images. Grade V5—Surface dull or matte and grossly discolored. 9.2 Physical Testing ofStain: 9.2.1 If a stain exists, grade the decoration on the test specimen and reference standard in accordance with one of the following physical test grades: 9.2.2 Physical Testing ofStain: Grade P1—Stain is easily removed by gently rubbing the hydrogen sulfide atmosphere exposed decoration with a dry paper towel. Grade P2—Stain is not completely removed by gently rubbing the hydrogen sulfide atmosphere exposed decoration with a dry paper towel, but can be removed by vigorous rubbing. Grade P3—Stain cannot be completely removed by vigor- ous rubbing with a dry paper towel.

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