|
| Absolute |
| |
A measure having as its zero point or base the complete absence of the entity being measured.
|
|
| Absolute pressure |
| |
The pressure above zero absolute, i.e., the sum of atmospheric and gauge pressure. In vacuum related work it is usually expressed in millimeters, or inches, of mercury.
|
|
| Acceptance sampling |
| |
A statistical quality control method that seeks to determine the quality of a product by sampling a small portion of it. It does not assure that 100 percent of the product is acceptable, but reduces the likelihood of acceptance of a defective product.
|
|
| Accumulator |
| |
A container in which fluid (generally nitrogen) is stored under pressure as a source of fluid power.
|
|
| Acre (a) |
| |
A unit of area used in English-speaking countries, equal to 4,840 square yards (0.405 hectares).
View: Metric / Imperial Conversion
|
|
| Across the grain |
| |
The direction at right angles to the length of the fibres and other longitudinal elements of the wood.
|
|
| Active falling area |
| |
The area within two tree-length radius of where a faller or a mechanized falling machine is operating.
|
|
| Actuator |
| |
A device for converting pneumatic or hydraulic energy into mechanical energy. A motor or cylinder.
|
|
| Adhesive |
| |
A substance capable of holding materials together by surface attachment. It is a general term and includes cements, mucilage, and paste, as well as glue.
|
|
| Adult wood |
| |
Wood which characteristically has relatively constant cell size, well-developed structural patterns, and stable physical behaviour; also called Mature wood.
|
|
| Adverse (grade) |
| |
Ascending grade in the direction of travel.
|
|
| Aeration |
| |
Air in the hydraulic fluid. Excessive aeration causes the fluid to appear milky and components to operate erratically because of the compressibility of the air trapped in the fluid.
|
|
| Aerial logging |
| |
A logging system which fully suspends the logs such as done by helicopters or balloons. Not to be confused with cable systems which use cables and supports.
|
|
| Age class |
| |
Any interval into which the age range of trees, forests, stands or forest types is divided for classification and use. Forest inventories commonly group trees into 20-year age class groups.
|
|
| Air velocity |
| |
The speed of airflow through the stickers, crossouts, and around the lumber expressed in feet per minute (fpm) or metres per second (mps).
|
|
| Air-dried |
| |
Lumber that was dried by exposure to air in a yard or shed, without artificial heat.
|
|
| Airflow |
| |
The pattern of air movement within a dry kiln. This pattern varies with kiln design, loading methods, and level of maintenance and operation.
|
|
| Allowable annual cut (AAC) |
| |
The volume of timber that may be harvested annually from a specific timber tenure.
|
|
| Allowable cut |
| |
The amount of wood that can be removed from a landowner's property during a certain time span, without exceeding the net growth during that same time on the property
|
|
| Along the grain |
| |
The direction parallel with the length of the fibres and other longitudinal elements of the wood.
|
|
| Alternate top bevel |
| |
A design for a circular saw blade where teeth are alternately beveled.
|
|
| American Lumber Standards |
| |
Provisions for softwood lumber dealing with recognized classification, nomenclature, basic grades, sizes, descriptions, measurements, tally shipping, provisions, grade marking, and inspection of lumber. The primary purpose of these standards is to serve as a guide in preparing or revising grading rules of the various lumber manufacturers' associations. A purchaser must, however, make use of association rules because the basic standards are not in themselves commercial rules.
|
|
| Amplifier |
| |
A device for amplifying the error signal sufficiently to cause actuation of the stroke control. Several types of servo amplifiers are used at the present time: electronic (DC, AC, phase sensitive, and magnetic) and mechanical.
|
|
| Amplitude of sound |
| |
The loudness of a sound.
|
|
| Analog |
| |
A continuous range of numbers or values.
|
|
| Anisotropic |
| |
Exhibiting different properties when measured along different axes. In general, fibrous materials such as wood are anisotropic.
|
|
| Annual growth |
| |
Layer of wood developed by a tree during a given year; same as annual or seasonal increment.
|
|
| Annual growth rings |
| |
The layer of growth that a tree puts on in one year. The annual growth rings can be seen in the end grain of lumber.
|
|
| Annular area |
| |
A ring shaped area - often refers to the net effective area of the rod side of a cylinder piston, i.e., the piston area minus the cross-sectional area of the rod.
|
|
| Anti-sap stain |
| |
A wood treatment used to prevent fungus from staining the wood.
|
|
| Anvil (swage) |
| |
The fixed jaw in a swaging device that supports the back of the tooth while the die or roller presses against the front of the tooth.
|
|
| Appearance grades |
| |
High-line regular board and dimension grades that include tighter restrictions on certain appearance characteristics, particularly wane.
|
|
| Arbor |
| |
The shaft on which a circular saw blade or chip head is mounted.
|
|
| Atmospheric pressure |
| |
Pressure exerted by the atmosphere at any specific location. (Sea level pressure is approximately 14.7 pounds per square inch absolute.)
|
|
| Axial force |
| |
A push (compression) or pull (tension) acting along the length of a member, expressed in kilonewtons (pounds).
|
|
| Axial stress |
| |
The axial force acting at a point along the length of a member divided by the cross-sectional area of a member, expressed in kilopascals (pounds per square inch).
|
