ASTM D3790

ASTM D3790 – Standard Test Method for Volatile Matter (Moisture) of Leather by Oven Drying

Description:

Significance and Use

4.1 The result obtained by this test is normally considered to be the moisture content of the leather 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 leather, although their amount in any normal leather 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 leather, such as protein fiber and chromium tanning salts, may retain moisture. Other materials, such as tannins and oils, 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 leather varies with (a) degree of grinding of the sample, (b) weight of sample taken, (c) temperature and time of the oven drying, (d) shape of the weighing container, and (e) 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.

Scope

1.1 This test method covers the determination of volatile matter (moisture) in all types of leather.

1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.