Calibrating Treadmill Speed
If you need an accurate measure of the treadmill's speed, or if you think that the speed dial is not working right, here is a simple way to check the calibration of a treadmill's speed. All you need is some chalk or colored tape, a ruler or tape measure, a string (optional), a stopwatch and a calculator.
- Measure the length of the belt. This measurement may be in the specifications of the treadmill, but you will want to check this yourself. You can either tape a piece of string to the treadmill and wind the belt around so that the start of the string does a complete loop. Mark and remove the string and measure its length. If you do not wish to use the string method, just move the belt along in short segments and use the ruler to measure each segment and total these for the total length.
- Mark the treadmill belt at any point along one edge with chalk (or stick some tape). Anything at all that you can see when the treadmill is going is suitable.
- Set the treadmill going to a particular speed (based on the speed dial).
- Watch the marker come around, and note each time it passes some point. When ready, start the stopwatch as the marker passes your view, and time how long it takes to see a set number of revolutions (e.g. 20 loops). At higher speeds you may wish to count a higher number of revolutions to get more accuracy.
- To determine the treadmill speed (distance / time), divide the distance (belt length x number of revolutions) by the time measured. For example, if the belt length was 3 meters, and it took 20 seconds for it to do 15 revolutions, then the speed is (3 x 15) / 20 = 2.25 meters/second (or 8.1 km/hr or 5 mph). You can also use this calculator to convert speed measures.
- Repeat this procedure for a range of treadmill speeds, and also repeat it with someone on the treadmill, to determine if the treadmill calibration still holds true when it is in use.