2.6 Instruments Used for Measuring Tree Height

A number of different instruments can be used to determine height. With the exception of the Merritt hypsometer, all work on the same principle of taking two slope readings.  The scales in each instrument are just housed in a different setting.

  • Clinometer – as shown in Chapter 1
  • Relaskop—see section 3.3
  • Laser range finder/electronic hypsometer (these do the math for you!)
  • Merritt hypsometer – illustrated below

Though not commonly used, the Merritt hypsometer on a Biltmore stick is an inexpensive tool for estimating tree height. It is based on the principle of similar triangles (Figure 2.15).

man holding a biltmore stick
Figure 2.15. A Merritt hypsometer on a Biltmore stick is held 25” from the eye to measure tree height.  The technician stands at a standard horizontal distance from the tree. Closing one eye, the technician places the bottom of the stick at stump level. Tree height is read off the stick where the tree top crosses the stick. In most cases, purchased Biltmore sticks are marked with “logs” instead of feet, but it is easy to construct a stick with a variety of units and better precision.




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2.6 Instruments Used for Measuring Tree Height by Joan DeYoung is licensed under a Creative Commons Attribution 4.0 International License, except where otherwise noted.