Forest Mensuration. Brack and Wood

Comparison instruments

• Abney (trigonometric-based),
• Haga (trigonometric-based),
• Blume Leiss (trigonometric-based),
• Spiegel Relaskop (trigonometric-based)
• Suunto clinometer (trigonometric-based).
• Vertex Forestor (sonic-range finder based)
• Criterion 400 (laser-ranger finder based)

Comparisons

• Precision: When properly calibrated and used, the Abney, Haga, Blume Leiss, Relaskop and Suunto have equal precision of about 2.5%. The Vertex and Criterion have a precision of less than 1%.
• Ease of Use: Haga, Blume Leiss and Vertex are easier to hold steady than Abney, Relaskop and Suunto. The Criterion is relatively heavy and may be difficult to hold for extended periods.
  • The Suunto causes eye-strain in some people due to the method of projecting the line of sight.
• Line of sight: Sighting with the Abney, Relaskop and Suunto is through a tube of narrow dimension or through the instrument. This restricted field of view (especially with the abney) is important under poor light conditions. The Haga and Blume Leiss have external sights. The Criterion has a rifle-style telescopic sight.
• Robustness: Ranked from best to worst:
  1. Vertex
  2. Releskop
  3. Suunto
  4. Blume Leiss
  5. Haga
  6. Criterion
  7. Abney
• Speed of use: Ranked from fastest to slowest:
  1. Criterion
  2. Vertex
  3. Blume Leiss
  4. Haga, Relaskop, Suunto
  5. Abney
• Price: Criterion over 10 times more expensive than other instruments. Relaskop and Vertex are similar in price but still much greater than the Haga, Blume Leiss and Abney which are similar in price. The Suunto is the cheapest instrument.
• Compactness: Ranked from most compact to least:
  1. Suunto
  2. Vertex
  3. Relaskop
  4. Haga, Blume Leiss, Abney
  5. Criterion

http://online.anu.edu.au/Forestry/mensuration/HGTCOMP.HTM
Cris.Brack@anu.edu.au
Tue, 7 Jan. 1997