500-61001-001 Rev. D
Page 24 of 30
Determining Specific Gravity
Determining the Species Setting
for an Unknown Species
The Species Setting Tables, based on specific gravity of solid wood,
are provided in this manual. If you do not know the species of the
wood you are using, or the specific gravity differs from the handbook
because of a different growing region, use the following procedure.
Determining the Specific Gravity
1. Select a sample of wood that is approximately 12% moisture
content, with all edges being true. Carefully measure the
dimensions of the sample using a caliper. You will need the
length, width, and thickness.
2. Convert these measurements to feet.
3. Carefully measure the weight of the sample.
4. Convert the weight to pounds.
5. Calculate specific gravity.
Example:
Length =
10 in.
10 in. / 12 in. = 0.833 ft.
Width =
7 ½ in.
7.5 in. / 12 in. = 0.625 ft.
Thickness =
1 ½ in.
1.5 in. / 12 in. = 0.125 ft.
Volume =
L x W x T
0.833 x 0.625 x 0.125 = 0.065 cu. ft.
Weight =
20 oz.
20 oz. / 16 oz. = 1.25 lb.
Specific Gravity:
(Weight / Volume) / Specific Gravity of water
(1.25 lb. / 0.065 cu. ft.) / 62.34 lb. / cu. ft. = 0.31
In order to ensure that the value obtained for the specific gravity is
statistically significant, a number of pieces must be measured and
the average determined. Use this value of specific gravity for the
species setting in the meter.
