In this Instructable, I'll show you how to use a clinometer to measure the height of a tall object (for help constructing your own clinometer from basic classroom materials, click here
What you will need;
Pen or pencil
Step 1: Pick a spot
Pick a spot to measure your object (I measured a telephone pole). You should be far enough away from your object that you can see the top of it, and you need to be on level ground with the base of the object. I like to set something down by my feet once I've picked my spot, so that I can easily come back to it.
Step 2: Measure angle
Here's where we bust out our handy clinometer. Look through the straw of your clinometer at the top of the light pole (or whatever object you're measuring). The weighted string should hang down freely, crossing the protractor portion of the clinometer. Read the angle shown, and subtract from 90° to find your angle of vision from your eye to the top of the pole (it can be helpful here to have an assistant to read the measurement while you look through the straw). Record your results on your paper.
From my spot, my clinometer (read by my assistant) showed 55°. Subtracting from 90°, that indicated that I looked at an angle of 35° to the top of the telephone pole.
Step 3: Measure distance
Once you have your angle of vision, use your tape measure to find the distance from the spot you're standing to the base of the object you're measuring (an assistant comes in handy here, too). We must know how far away you are to accurately calculate the height.
My spot was 15.6 meters from the base of the telephone pole I measured.
Step 4: Find your eye-height
The last piece of data you need to calculate the height of your object is the height from the ground to your eye (your eye-height). Have your assistant help you measure this using your tape measure.
My eye height was recorded for this example as 1.64 meters.