AY Honors/Forestry/Answer Key

Template:Confusing Template:Internallinks Template:Refimprove Template:Wikify The clinometer is a common tool used by foresters to measure standing tree height

How It works

Clinometers work off of basic trigonometric principles. Multiplying the tangents of angles to the base and top of the object and then adding them together gives the observer the total height of the object.

File:Illustration of the basic trigonometric principles used by a clinometer.JPG

Usage

The forester stands at a fixed distance from the base of the tree. The most common distances are 50, 66, and 100 feet. To obtain accurate readings it is best to use taped measured distance instead of pacing distances. For the most accurate readings it is best to use a fixed distance that is equal to or greater than the height of the tree you are measuring. The observer then sties to the top of tree, if total height is the desired measurement. If merchantable height is the desried measurement the observer sites to a point on the tree where no more merchantable timber can be used. This point varies from sawmill to sawmill depending if the tree will be used for pulp or timber. The observer then measures to the bottom of the tree and adds the two figures together. This will be the height of the tree. Always measure a leaning tree so that the tree is leaning to the left or right. Measurements should never be taken with the tree leaning toward or away from the observer because this will affect the accuracy of the measurement. The clinometer is also commonly used by foresters to obtain the percent slope of terrain. This measurement is based on the same trigonometric principles described above.

Manufacturers

Suunto

Haglöf

Brunton

Silva

See Also

Inclinometer

References

Avery, T.E. and Burkhart, H.E. “Height Measurement Principles.” Forest Measurements 5th Edition. McGraw-Hill, 2002. 154.

Calvert, J.B. “The Clinometer.” 2003.