SUUNTO PM5 - Manual (Page 5)

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PM-5/1520
OPTICAL HEIGHT METER
Suunto Height Meter PM-5/1520 is an instrument for measuring heights, especially
heights of trees, with great accuracy and speed. The body of the instrument is
corrosion-resistant anodized aluminium-alloy. The scale card runs on a special
bearing in a hermetically sealed plastic container filled with a liquid which guarantees
that it runs freely and stops quickly. The liquid will not freeze, retains full damping
properties in working conditions and eliminates irritating scale vibrations.
INSTRUCTIONS FOR USE
When measured from distances of 15 m and 20 m, tree heights can be read straight
off the instrument’s scales. The readings should be doubled when measuring from
distances of 30 m and 40 m. The Suunto Height Meter can also be used to determine
the angle of a gradient. This is done by taking a sighting along the line of a gradient
using the 20 m scale on the left of the instrument. The reading obtained can be
checked in the conversion table on the back of the instrument to obtain the angle.