The SILVA CM Heightmeters equipped with a Relascope are used to determine the volume of timber in forest. The Relascope method is a well known method of timber volume estimation in the forestry industry. The Relascope models have to be used in combination with a timber volume table (included with the Relascope-models). The estimation of the timber volume per ha (hectare) with a Relascope, is based upon the measuring of the base area of the trunk surface (at 1.3 metres from the base of the tree) in combination with the average height of the trees. With the above mentioned data, the timber volume/ha can be read out in the timber volume table.
1. Position yourself in the centre of a tree stand that is representative for the average of the forest.
2. Hold the end of the chain against your cheek and sight through the slot on the edge of the Heightmeter towards a position 1.3 metres up the tree.
3. All trees wider than the slot are counted. Every second tree having the same thickness as the slot is also counted. Proceed counting trees as explained, as you turn around (360°).
4. The number of trees counted represents the current base area of the forest.
5. Determine the average height of the trees using your heightmeter.
6. Read out the current timber volume/ha at the intersection of the obtained base area column and the average height of the trees row in the timber volume table.
The SILVA ClinoMaster Heightmeter Relascope is equipped with two multiplication factors (1 and 2). By using the ring on the middle of the chain the slots relative opening will become twice as wide, which means that the number of trees counted has to be multiplied by two to obtain the correct base area value.
