Log graders and scalers estimate the market value of logs.
Did you know an average-sized log (about 12 feet tall and 16 inches in diameter) can weigh over 1,000 pounds? However, this doesn't take into account the kind of tree. Red oak weighs more than red maple, and hickory is somewhere in between. Regardless of the type of wood, a semi-truck loaded with logs can weigh over 20 tons. But before the logs leave the site, they first must be inspected. This is the job of log graders and scalers.
Log graders and scalers inspect logs and assign a grade according to the quality of the wood. They weigh or measure logs, compute dimensions, make deductions, and estimate market value. Using signals, graders and scalers work together to safely move logs.
Log graders and scalers climb onto log trucks and measure loaded logs. Logs may also be rolled out onto the ground to be scaled. Occasionally, they measure logs that are floating in ponds. They do this by walking and balancing on the logs. Log graders and scalers use tape measures to measure the length of each log and the diameter of both the large and small end. Graders and scalers enter the length and diameters into calculators or hand-held computers. Using an approved scaling formula and special software, they calculate the volume of wood. They use weigh stations to weigh trucks that are loaded with logs. By subtracting the weight of the unloaded truck, they determine the weight of the logs. Most logs are scaled as a group by their weight, but occasionally they are scaled one at a time. Sometimes, graders and scalers will saw logs into lengths.
Graders and scalers use different guidelines for each tree species. They make deductions for knots, holes, and charred, missing, or rotten wood. Then they estimate the market value based on the amount of useful wood in the logs. They factor tree species and market prices into their estimates, using standard formulas. Graders and scales record the size, weight, and market value of each load of logs. They forward this documentation to administrative centers for review. They may paint the grade on the logs.
Buyers and sellers want value estimates that they can agree on. Thus, they often use independent graders and scalers who do not work for either the buyer or the seller. These independent opinions are considered more trustworthy and become the basis for price agreements. When there are disagreements, senior scalers may check the value by doing the work over again.
Graders and scalers base their volume reports on several methods of computing. They must use methods that are acceptable to both buyers and sellers. For example, Canada uses the metric system and the United States does not. Japan has its own approach. Because these nations are trading partners, graders and scalers must know how to use each country's methods.
By recording the weight of logs on loaded trucks, owners and government agencies can protect against fraud and theft of valuable wood.