Question

what are the function of clinometer?and inspiration we learn from clinometer

Answer 1

The clinometer is an optical device for measuring elevation angles above horizontal. The most common instruments of this type currently used are compass-clinometers from Suunto or Silva. Compass clinometers are fundamentally just magnetic compasses held with their plane vertical so that a plummet or its equivalent can point to the elevation of the sight line. A better clinometer (I believe) is the Abney hand spirit level or clinometer, where the object sighted and the level bubble can be seen simultaneously, so that the index can be set accurately. An Abney clinometer is shown in the photograph. A spirit level is so-called because it contains alcohol in a tube of large radius, in which the bubble moves to the highest point. Spirit levels are used for accurate surveying, although automatic levels that go back to the principle of the plummet are now frequently found, and are easy to use.

I have an inexpensive 5" Abney clinometer made in Japan that was once sold by Brookstone, while they still had cheap, useful things to sell. It is no longer obtainable from Brookstone. The References contain a source for a nice, rather inexpensive brass clinometer that should be a pleasure to use. I have bought from this source, and can recommend it. Abney clinometers are available from surveying supply houses for considerably more money, over $100. Captain William Abney was at the School of Engineering at Chatham, England in the 19th century, and invented many ingenious surveying instruments.

The Abney clinometer has a sighting tube with an angle scale reading from -90° to +90°, and a spirit level with a Vernier index that can be moved along the scale while the user looks through the sighting tube. A small mirror and lens makes the level bubble visible in the field of view. When the object is aligned with the crosshair in the sighting tube, the spirit level is rotated so that the bubble is bisected by the crosshair, as illustrated in the diagram. Then, the elevation of the line of sight can be read off on the scale. The Vernier can be read to 10', but it requires a magnifier to do this. The clinometer can read easily and accurately angles of elevation that would be very difficult to measure in any other simple and inexpensive way.

A fairly common use of a clinometer is to measure the height of trees, which is easily done. A point should be marked with a stake as far from the centre of the trunk of the tree as its estimated height, so that the elevation angle is about 45°, which gives the best "geometry." This distance D is measured with a tape. The observer then stands over the stake and sights the top of the tree, finding its elevation angle θ. The height H of the tree is then H = D tan θ + HI, where HI, the height of instrument, is the height of the observer's eye. - BY RANDEEP BHASHMA

Answer 2

A clinometer is used to measure angles. This is the method used by foresters to measure the height of a tree. The clinometer only works for measuring height when the observer is standing exactly one "chain" length away from the tree (66' or 100 links).