Measuring the RPM (revolutions per minute) of electric motors or the devices they drive can be a useful diagnostic tool. It can help in the proper drive system of gears or belt drive to deal with the feeding problems of the application. A speed adjustable timing light can become a valuable tool to find the exact RPM of almost any rotary machine. Following a necessary process, you can measure the RPM of most rotating circular devices.
- Use the white chalk or black marker and mark a small white line or black dot at the end of the spin axis or pulley. The more beautiful the edge or point, the more accurate will be the sighting of the determination of the speed of the axis.
- Connects the timing light adjustable in speed and unit tests. You should be able to turn the adjustment dial on the back of the light and change the “flashes” per second or minute. Also, keep in mind that the timing light will have manufacturer indications on the dial to identify timing flash speeds. Depending on the manufacturer, the timing light could come with a conversion table to convert the values of the flashing dial per second in minutes.
- Start the electric motor or similar device and let the unit reach its maximum speed; this may take a few seconds depending on the application.
- Illuminates the timing light in the place where the brand is located. The white line or black dot should start to light up. The goal is to slowly adjust the speed dial of the timing light to make the line or point stop. As you adjust the speed of the timing light on the line or point, you could move to the left of the center (to slow the speed) or to the right of the center (to accelerate the speed). You want the brand to stay in the center of the flashlight and appear as a reliable brand. Once you have found this image, read the speed on the dial indicator, this is the speed at which the axis is spinning.
- Calculate the speed in RPM from a dial reading of the timing light that is 60 flashes per second (DPS). Since there are 60 seconds in each minute, you can multiply 60 seconds per minute by 60 flashes per second, and the result will be 3600 RPM.
Be very aware that the shaft is sometimes turning at high speed. Once the flash is set correctly, the axis “will look” that does not move at all. Do not touch the axis of rotation with your hand due to this optical illusion; you can suffer serious injuries.