Clinometer Scales!
There are a number of different scales on the clinometers you'll find in our catalogs and on our Web site. Here is an overview:
1. First up, a 66 foot scale (Brunton) is the same as a Topographic scale (Suunto). This scale is going to give a direct reading of a height of the object being measured. By walking 66 feet (which is 1 chain) from the base of the tree the scale will give a direct reading in feet of the height of the object. Metric versions are basically the same, but rely on meters not chain lengths.
2. The Percent scale can be used to get the percent grade of a slope or to figure heights as well. This scale allows you to be any distance from the tree and still calculate the tree height. For example if you read to the top of the tree at 72% and at the bottom to -6% and you are 100 ft from the base of the tree. It would be (.72-(-.06)*100=78 feet tall.
3. The Degree scale simply gives the angle in degrees away from being level. This is very useful in geology when determining the strike and dip of land forms. It also greatly aids in maneuvering in a submarine, but I rarely speak to naval admirals about this.
4. The Secant scale has one major use—working on sloped terrain. Let's say you're at the bottom of a large hill, and you need the height of a tree growing at the top of that hill. The secant scale will allow you to do this without having to take several different measurements.
1. First up, a 66 foot scale (Brunton) is the same as a Topographic scale (Suunto). This scale is going to give a direct reading of a height of the object being measured. By walking 66 feet (which is 1 chain) from the base of the tree the scale will give a direct reading in feet of the height of the object. Metric versions are basically the same, but rely on meters not chain lengths.
2. The Percent scale can be used to get the percent grade of a slope or to figure heights as well. This scale allows you to be any distance from the tree and still calculate the tree height. For example if you read to the top of the tree at 72% and at the bottom to -6% and you are 100 ft from the base of the tree. It would be (.72-(-.06)*100=78 feet tall.
3. The Degree scale simply gives the angle in degrees away from being level. This is very useful in geology when determining the strike and dip of land forms. It also greatly aids in maneuvering in a submarine, but I rarely speak to naval admirals about this.
4. The Secant scale has one major use—working on sloped terrain. Let's say you're at the bottom of a large hill, and you need the height of a tree growing at the top of that hill. The secant scale will allow you to do this without having to take several different measurements.
2 Comments:
Your description of the secant scale is not very clear. This scale is used to determine slope distance by multipling the clino reading by a desired horizontal distance. If your desired HD is 100 feet (or meters) then you can read your corrected slope distance right off the clino. I’ve used this scale mainly to determine large plot radii on steep slopes. If I was working on a 55% slope the secant reading would be 114 and if I needed to know where the edge of a 1/10 acre plot was I would multiply 1.14 by 37.24 (horizontal plot radius) for a SD of 42.45
Tom Schreiber
RG Forestry Consultant
Hoodsport, WA
By
Anonymous, at 1/29/2007 2:53 PM
Thank you Tom. Your description is so much easier to apply in the field.
By
Anonymous, at 2/15/2007 12:27 PM
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