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ASTM D4903-99(R2020) pdf free download

ASTM D4903-99(R2020) pdf free download.Standard Test Method for Total Solids and Water in Vegetable Tanning Material Extracts
1. Scope
1.1 This test method is intended for use in determining the total solids and water in extracts of vegetable tanning materi- als. The test method is applicable to solutions of liquid, solid, pasty, and powdered extracts, and to extracts of raw or spent materials. 1.2 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. 1.3 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.
5. Apparatus
5.1 Tannin Dish—Crystallizing dish, borosilicate glass, 50 mm tall, 70 mm outside diameter. The bottom corner shall be rounded to a radius of 6 mm, the bottom shall be flat and not cupped in the center, and the top edge shall be rounded and polished. 5.2 Pipet, 100-mL capacity, preferably with a wide orifice approximately 2.4 mm ( 3 ⁄ 32 in.) diameter and 15 to 25-s delivery time. 5.3 Drying Oven—A forced-air convection oven (or mechanical-convection draft oven) capable of maintaining a temperature of 100 6 2.0 °C. 5.4 Thermometer—Accurate to 62.0 °C, used to check and monitor the oven set point. 5.5 Dessicator—Any convenient form or size.
6. Test Specimen
6.1 The specimen shall consist of 100 mL of a solution prepared as described in Practices D4901, D4905, and D6405.
7. Procedure
7.1 Thoroughly mix the solution, prepared as described in Practices D4901, D4905, and D6405, by inverting and shaking 8 to 10 times, taking care to ensure that all insoluble matter is uniformly dispersed and none is left adhering to the walls of the flask. Immediately pour a 150-mL to 250-mL portion (approximately) into a bottle or other suitable container, stoppered or covered, and retain until the soluble solids and non-tannins are ready to be pipetted (see Practice D6404). Where the analysis is being performed in a constant tempera- ture room, however, the specimen may be pipetted from this portion at any convenient time. At the proper time, thoroughly mix this secondary portion by shaking, or stirring, so that the insoluble matter is uniformly distributed throughout the liquor and none remains adhering to the walls of the container. Immediately rinse the 100-mL pipet with the liquor rejecting the rinsings. Then stir the liquor well, avoiding production of air bubbles and foam, and while stirring immerse the tip of the rinsed pipet and fill pipet quickly by suction. Bring the level to the mark as quickly as possible, and transfer the 100-mL specimen into a tared evaporating dish. (Since tan liquors are very liable to foam and since they may contain large amounts of rapid-settling insoluble matter, conduct the final mixing so as to avoid foam formation. Fill and bring the pipet to the mark as quickly as possible.) Place the dish containing the specimen, together with the other dishes containing the specimens for soluble solids and non-tannins (Test Methods D6401 and D6402), in the drying oven and evaporate and dry as specified in Practice D4902.
10. Precision and Bias
10.1 This test method is adopted from the procedures of the American Leather Chemists Association, 3 where it has long been in use and where it was approved for publication before the inclusion of precision and bias statements was mandated. The original interlaboratory test data are no longer available. The user is cautioned to verify by the use of reference materials, if available, that the precision and bias of this test method is adequate for the contemplated use. 10.2 The total solids content obtained by this test method is operationally defined as the dried solids weight ofthe specimen collected after drying the specimen. The water content is defined as the difference between 100% and the total solids of the sample. There is no independent measure of the true total solids and water content ofa sample. Therefore the bias cannot be related to the true total solids or water content ofthe sample.

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