Used in variable plot and Three P sampling. American Scale reads in English units (sq. ft./acre, inches, feet). Use where trees are smaller than 96” dbh on level or steep terrain. Metric Scale reads in metric units (sq. m/hectare, centimeters, meters). Excellent for a variety of forest conditions and tree sizes. Wide Scale is designed for metric measurements (diameter measurements convert to inches or centimeters). Recommended for trees larger than 244 cm (96”) dbh. Works on level or sloping terrain. CP Scale is ideal when metric or English measurements are desired (basal area in sq. m/hectare only). An optional Accessory Light illuminates scale in the dark. Leather case and illustrated booklet included.
General instruction for use of the Relaskop for measuring diameter:
- Measure the desired horizontal distance ( H metres) from the base of the tree ( or point directly beneath the desired tree site) to a location where the required point ( eg change in diameter) can be seen. Note that you must be at least 5 m away for every 20 cm anticipated diameter.
- Sight at the required point, while holding the break button to allow the scales to freely rotate.
- Read from the diameter scale once the scale has settled the number of large bands ( with the number 1 printed on them) ( L) ; the number of small bands ( 4 narrow bands immediately to the right of the large 1 band) ( S) ; and an estimate of any fractional small band ( s) . Estimate the fractions of the small band as 0.2 ( just into the band) , 0.4 ( almost half) , 0.6 ( just over half) , 0.8 ( amost full narrow band)
- Diameter is calculated as d ( cm) = H* ( L+ 0.25* ( S+ s) ) * 2
- Check to ensure the diameter appears correct. Note that L will be 0 or 1, S will be 0, 1, 2, 3, 4 and s will be a fraction less than 1.0.