Значение и использование

The specific gravity of wood gives an excellent measure of the amount of wood substance present in a sample. Thus, it may serve as a valuable indicator of the amount of wood pulp that could be produced, the workability of the material, or the strength characteristics of a specimen or a species. It should be recognized that specific gravity varies between trees, within a tree, and between species. Since the specific gravity of wood substance is practically constant for all species (approximately 1.53), it is apparent that individual specific gravity values are indicative of the amount of wood substance present. It affords a rapid and valuable method for selection of wood for specific uses.

It may be desirable to know the specific gravity of a living tree, a structural member already in place, a log cross section, a segment of a research element, or the earlywood or latewood layer. The specimen thus may be large or small, regular or irregular, and at a variety of moisture contents. These test methods give procedures that include all of these variables and provides for calculation of specific gravity values to degrees of accuracy generally needed.

Область применения

1.1 These test methods cover the determination of the specific gravity of wood and wood-based materials to generally desired degrees of accuracy and for specimens of different sizes, shapes, and moisture content conditions. The method title is indicative of the procedures used or the specific area of use.

Section Test Method A—Volume by Measurement7 Test Method B—Volume by Water Immersion8 Test Method C—Flotation Tube9 Test Method D—Forstner Bit10 Test Method E—Increment Core11 Test Method F—Chips12

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 appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.