How Is a Laser Tachometer Used?

Automotive purposes

A laser tachometer can be used to measure the number of rotations per minute (rpm) of a spinning shaft or a disk. Laser tachometers have the advantage of being able to measure rpm without being directly in contact with the rotating shaft. Tachometers used in automobiles and other engines measure the rotation speed of the engine's crankshaft. Most engines have an upper limit of rpm under which they can be operated without causing excessive wear and tear and damage to the rest of the engine, and a tachometer will allow a driver to be prevent running their engine at potentially dangerous rpm. They can also assist a driver in choosing appropriate gear settings.

Engineering uses

Laser tachometers are especially useful for mechanical engineering and design. When a piece of machinery is being designed, its rotational velocity must be carefully honed for all of the other moving components to work properly. A laser tachometer can measure rpm accurately, remotely and can also be used to measure the rotation of gyroscopes. Gyroscopes are often used to measure changes in acceleration and are often also used for balancing and orientation of instruments.

Uses for rail vehicles

One of the main uses for laser tachometers is in rail vehicles, especially ones from mass transit. Laser tachometers are set up to beam on the wheels. By measuring revolutions of the wheel the tachometer is also able to give an accurate measurement of velocity. This is critical for the automated signaling that most public transit systems use for their rail traffic to help guide multiple trains which are often using overlapping tracks. One danger, however, of using laser tachometers is that they rely on wheel rotation to measure speed. Because the wheels and rails are very slick, there is always the danger that the wheels will slip or skid, which will lead to massive errors in the measurements from the tachometer. As a result, the systems need to either have a backup method for measuring speed, or to automatically filter these incorrect results.