A stroboscope is an instrument used to make a cyclically moving object appear to be slow moving or stationary. The principle is used for the study of rotating, reciprocating, oscillating, or vibrating objects. Machine parts and vibrating strings are common examples. In its simplest form, a rotating disc with evenly spaced holes is placed in the line of sight between the observer and the moving object. The rotational speed of the disc is adjusted so that it becomes synchronized with the movement of the observed system, which seems to slow and stop. The illusion is caused by temporal aliasing, commonly known as the stroboscopic effect.

Stroboscope is an instrument used for making a cyclically moving object appear to be slow moving or stationary. It is used in the study of rotating, reciprocating, oscillating or vibrating objects. It is ideal in the inspection and observation of moving parts by freezing or slowing down the action of an object. It plays an important role in the study of stresses on machinery in motion, and in many other forms of research.

Stroboscopes are ideal for non-contact RPM measurements and for observation of fast, repeated motions of machines. The revolving machine component can be visualized as a stop-motion picture by adjusting the light flashes synchronously to the rate of the movement. With the multiplier/divider function, the actual RPM or frequency of the motion can be determined accurately.