Understanding Log Measurement in Different Countries (Part 2)

Yesterday, we introduced some common measurement methods used in various countries around the world, especially those exported to China (click to view). Today, we continue from the previous issue and introduce other measurement methods.

6) Hoppus Measurement

It was invented in 1736 and is said to be the earliest method of measuring logs that is still in use today.

Commonly found in Myanmar and India, such as Indian teak logs.

The specific steps are: measure the "waist circumference" of the log in the middle => divide by 4 to get the "mid-quarter girth" => imagine this number as the side length of a cuboid and calculate the volume (that is, square the number and multiply by the length).

Similar to North American board materials, there's a concept called the Hoppus foot (Hft), with the conversion relationships as follows:

1 HFT = 0.036064 m³ = 1.273 cubic feet

7) Doyle measuring instrument

Commonly used in American hardwoods

The principle is to imagine a log with diameter D as a cube with side length D-4, calculate the volume, and then subtract 25% for saw kerf damage. Therefore, the formula is:

(D-4)²xLx0.75/12 (D is the diameter in inches, L is the shearing feet)

8) International measuring method

A method for measuring American hardwoods was created by a brilliant man named Judson Clark. It's said to be the most accurate calculation method to reflect the actual yield of logs, because it takes into account an approximately 1/2 increase in log diameter for every 4 feet, and also an approximately 1/8 increase in kerf for board cutting. Then it presents a bizarre formula:

Unfortunately, this measurement method is rarely used in practice.

9) Weight measurement method

Perhaps to save time, or perhaps because the value of logs doesn't justify the laborious task of measuring each log individually, the total volume measurement method works by measuring the cubic volume of logs at a certain weight (e.g., 10 truckloads net weight), and then using this average to calculate the volume of a large quantity of logs (e.g., 100 truckloads). This method is commonly used for small-diameter North American softwood and pulpwood.

10) Bundle inspection method

After stacking or loading the logs into containers, measure the length, width, and height of the entire stack/bundle, and then multiply by the compaction coefficient of 0.6.

This method is often used when the logs are of low value or have been affected by natural disasters (such as strong winds, forest fires, insect infestations, etc.) and need to be sold quickly. This method of measurement is relatively crude, and buyers often get a significant overestimation of the logs' size.

In conclusion, due to differences in history and tradition in different regions of the world, log measuring methods vary, sometimes significantly. When importing logs, it is essential to first understand what measuring method is used to determine the price quoted for the logs.