ASTM D763-01 pdf free.Standard Specification for Raw and Burnt Umber Pigments.
1.1 This specification covers the pigments commercially known as raw umber and burnt umber.
1.2 The values stated in SI units are to be regarded as the standard. The values given in parentheses are for information only.
2.1 Dry Pigments- The pigments shall conform to the following requirements:
2.2 Raw Umber- -The pigment shall be in a soft, dry form and shall be a hydrated oxide of iron (together with such manganese that is naturally as sociated with it) permeating a siliceous base and shall be free of admixtures of other substances except cartbon pigments. The pigment shall conform to the requirements for composition prescribed in Table l.
2.3 Burnt Umber- -The pigment shall be produced by the calcination of raw umber and shall be free of admixtures of other substances except carbon pigments. The pigment shall conform to the requirements for composition prescribed in Table 1.
2.4 Paste in Oil- For both raw and burnt umber, the paste in oil shall be made by thoroughly grinding the pigment with linseed oil (with or without a small amount of volatile thinner) together with (where necessary) small amounts of wetting or dispersing agents to produce a paste or semipaste of satisfactory consistency. As received, it shall not be caked in the container and shall break up readily in linseed oil to form a smooth paint of brushing consistency. It shall mix readily in all proportions, without curdling. with linseed oil, turpentine, or volatile petroleum spirits, or any mixture of these substances.
3.1Two samples shall be taken at random from different packages from each lot, batch, day’s pack, or other unit of production in a shipment. When no markings distinguishing between units of production appear, samples shall be taken from different packages in the ratio of two samples for each 4540 kg or 10 000 lb, except that for shipments of less than 10000 Ib, two samples shall be taken. At the option of the purchaser, the samples may be tested separately or after blending in equal quantities the samples from the same production unit to fom a composite sample.ASTM D763 pdf download.