A photo tachometer functions by using what technology?

A photo tachometer operates by using light as a means to measure rotational speed. It typically works by directing a beam of light, often a laser or LED, at the rotating shaft of a motor. As the shaft rotates, it reflects the light back to the tachometer. The device then detects the interruptions in the light beam caused by the shaft's rotation, allowing it to calculate the speed based on the frequency of these light reflections.

This non-contact measurement method makes photo tachometers advantageous for measuring the speed of rotating objects without interfering with their motion or requiring additional physical components in contact with the rotating parts. Such technology is precise and can operate in various lighting conditions, not limited to daylight. The method is robust in industrial applications, making it common in advanced pneumatic systems for accurately gauging performance metrics.