by Dr. W. Bitterlich

The most popular hand-held forestry instrument.

The Relaskops are principally known in connection with angle-count sampling (ACS), a method which determines basal area density in forests by a simple counting method.

The Relaskop automatically corrects for any inclination in the line of sight, making it possible to easily find the stand basal area in square meters per hectare either at breast height (1.3m above the ground) or any other height.
The Relaskops offer quite a few other measurement applications in practical and scientific forestry.

For example:

  • Relaskops are the principle instrument of “variable plot sampling”, which has the special advantage of selecting a basal-area weighted distribution. In addition, the appropriate stem numbers per hectare can be derived from the ACS selection sample.
  • Measurement of total tree height, or heights to particular upper stem diameters.Measurements of upper stem diameters at particular heights.
  • Determining the horizontal distance, with automatic correction for the angle of inclination.
  • Quick determination of the “slenderness” (height/diameter ratio) of standing trees.
  • Determination of form heights, and the volumes of standing trees by Pressler’s formula.
  • Determination of slope angles

For points 2 and 3 we recommend for Precision Measurements for research the following:
Spiegel-Relaskop with CP Skala with Micro Attachment and Tilting Head

Relascope Details