Home Made Clinometers (For measuring altitude / elevation/ vertical angles.)

Find a circular 360 degree protractor with a solid center and a 6" or longer clear plastic ruler that has a line down the center in the long direction. Scribe and carefully cut a straight line from the edge of the protractor from 110 to 250 degrees. Plastic cutters are available and a sharp knive can scribe plastic in the opposite direction as cutting. Drill a small hole in the exact center of the protractor the size of a small bolt or thumb tack. Drill another hole on the center line at one end of the ruler. Attach the two with a very small bolt or tack. You can cover a tack point with an eraser. Add a counterweight like a large washer to the center bottom of the ruler as a counter weight. Make sure it hangs vertically and swings freely. Adjust the counter-weight with the cut edge of the protractor against the bottom of a level that has been leveled.

Homemade Clinometer

The Sun's Shadow

Measuring Sun Set Angle at Horizon

To use this clinometer, site over the cut edge at 110 and 250 degrees with the ruler pendulum hanging down free. DO NOT LOOK AT THE SUN. When the cut edge is pointed at what you want to measure the altitude of, press the ruler and protractor together and read the angle from the scale. You can watch the sun's shadow on the 110/250 edge by pointing it at the sun and looking at the sun's shadow on your finger. Make sure you use the 0 to 90 degree scale.

If you make one from a 10" or 12" protractor and carefully adjust the counter-weight, it can read angles with up to 1/2º degree accuracy. Most larger protractors have a center bar and you must file an notch in the exact center and use tape to make a center pivot. Don't cut the protractor at 110 and 250 points but attach a bar as a pointer. Most computer sun position programs are not this accurate and you usually don't need this accuracy. Navigation and surveying programs are much more accurate.

Sun's Shadow from Large Home Made Clinometer

Another style: Buy a "Deck and Rafter Square" from Ace Hardware or a "Polysquare" from other hardware stores. Attach a string and weight to the notch at the "0" inches. Let the string hang and measure the angle the inch scale is pointed at or held against. Point it at the sun and watch the shadow on your hand. Read degrees with string.

Measuring Sun's Altitude with PolySquare

To determine the sun's approximate path at sunrise and sunset, set the angle of the clinometer at what angle the sun moves in relation to the horizon. (See General Sun Information)

Suunto Tandum Sun Set Angle

Home Clinometer Sun Set Angle

Angle Finder Sun Set Angle

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