Types of Trees
There are two basic type of tree from which most lumber is produced. The first
type are softwood trees,
which produce softwood lumber. The softwood lumber industry is primarily geared towards the
construction industry. Softwood is very plentiful, and coniferous trees grow at a much faster pace
than hardwood trees. Evergreens or coniferous trees, are cone-bearing or needle-bearing trees.
Common examples are pine, fir, cedar, and redwood.
Hardwood trees are much slower growing, shedding their leaves in fall and ,
for the most part,
are dormant throughout the winter months. Hardwood lumber originates from these
broad-leaf deciduous trees. Some common hardwoods are walnut, mahogany, maple, birch, cherry,
and oak. Hardwoods are the preferred choice for the furniture building industry and the flooring industry,
due to their durability and less likelihood of indentation.
Trees can be categorized into two basic types, hardwoods and softwoods. In
the growth rings are composed of both earlywood and latewood. Earlywood is produced in
the high growth or spring stage, whereas latewood is produced in the latter part of summer and fall.
Therefore, earlywood is typically wider within the growth ring.
The hardwood tree has the same annual growth rings, but growth will typically
be consistent and
uniform across the cross-section of the tree trunk.
The outer portion of a tree forms the sapwood, which carry essential nutrients
through the tree trunk
from the root system to the branches and leaves. Every year, the sapwood is replaced with a
new layer of sapwood, causing the older sapwood to become the outer layer of the heartwood.
The heartwood does not serve a useful active purpose, but rather, forms the bulk of the tree trunk.
The sapwood is usually much lighter than the heartwood, and is therefore sometimes
from the heartwood before processing.
Knots can be found along boards cut from a tree. The knots are caused by branches
have or might not have successfully grown from the tree trunk.
ProTable is a single axis measuring system designed for quick and affordable length or width measurements.
ProTable is built with rugged aluminum extrusion and steel bearings to insure smooth operation and to minimize orthogonality, Abbé, and cosine errors. Both jaws are designed for extended use.
ProTable was designed for error-free operation and can be shipped fully assembled.
Dual Measurements: With ProTable, you can measure or position your system
in absolute mode, switch to incremental mode for relative measurements, and
return to the absolute mode with no loss of measurement or accuracy.
Easy Operation: Front panel settings for Zero, Plus & Minus Offsets, Data Hold, Data Send, and Units Mode.
Choice of Measurement Units: The Digital Display can display readings in Millimeters, Centimeters, Decimal inches or Fractions. Fractions can be displayed in 16ths, 32nds, or 64ths.
Battery Power: Two AA batteries last 6-8 months (average). Since there aren't any power wires to install or maintain, a ProTable with legs and casters can be a portable measuring system.
One year warranty.
SPC Output: Plug in your favorite SPC data collection system and log readings as you see them on the display. (Output in decimal form only; fractions display outputs in decimal inches.) The SPC data can also be converted to RS232 or USB.
"Theoretically, one cubic foot (of wood volume) contains 12 board feet. For average values 6 should be used, though 10 is a conventional figure for approximations. When the conversion applies to trees, ratios of 3 to 8 should be applied (U.S. Department of Agriculture, 1935)."
The Pulpwood Measurement
The standard measurement unit for wood used for paper and fuel is the cord . This is a stack of wood 4 ft. x 4 ft. x 8 ft. containing approximately 128 cubic feet of bark, wood and air space. Air space can actually be as high as 40 percent but usually averages 25 percent. You can see where weight can be advantageous here.
Pulpwood purchases by weight are very common and weight per cord varies widely with species and geography. A hardwood pulpwood cord generally weighs between 5,400 pounds and 6,075 pounds. A pine pulpwood cord weighs between 4,700 pounds and 5,550 pounds. You really need to determine your local average weight by species when measuring cordwood.