Active Standard ASTM D6658 | Developed by Subcommittee: D31.02
Book of Standards Volume: 15.04
Historical (view previous versions of standard)
Significance and Use
4.1 The result obtained by this test is normally considered to be the moisture content of the wet blue or wet white sample. This result is used to correct all other chemical tests to a moisture-free basis.
4.2 Materials that are volatile under these conditions, other than water, may be present in the wet blue, although their amount in any normal wet blue would be expected to be a very small percentage of the total volatile matter.
4.3 Under the conditions of this test, certain materials in wet blue, such as protein fiber and chromium tanning salts, may retain moisture. Other materials, such as natural animal fats, may be oxidized. Both of these effects produce negative errors in the moisture determination.
4.4 The amount of volatile matter (moisture) released by a given sample varies with (a) method and time of sample preparation, (b) weight of sample taken, (c) temperature and time of the oven drying, (d) type of oven (gravity versus mechanical convection) used.
4.5 Because of the above unknown errors, the result of this test is a purely arbitrary value for the moisture content of the sample. It is, therefore, essential that the method be followed exactly in order to obtain reproducible results among laboratories. This is particularly true if other chemical analytical tests being performed on the same sample are reported on the moisture-free basis.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
D6659 Practice for Sampling and Preparation of Wet Blue for Physical and Chemical Tests
ICS Number Code 59.140.10 (Processes and auxiliary materials)