Laser caliper measuring principle: laser scanning measurement

The beam sent by laser diameter gauge measurement system of laser rotating mirror and scanning optical system by polyhedron scanning, forming a continuous high speed scanning beam and the optical axis parallel, high-speed scanning of the workpiece is placed in the measurement area, and is received by the photoelectric receiver on the opposite side of the workpiece in place, projected onto the photoelectric photoelectric receiver of the light is shut off in the beam scanning the workpiece, so the photoelectric receiver output signal analysis, can be a relationship between the diameter of workpiece data.

In order to ensure the high accuracy and reliability of the measurement, the optical scanning measurement system must meet the following three basic requirements:

(1) the laser beam should be irradiated vertically to the surface of the measured object.
(2) the beam must have a uniform linear scanning motion on the surface of the object.
(3) the scanning time must be measured accurately.

In reality, the scanning speed is not a constant, but changes with the change of the angular displacement of the scanning mirror, which will result in the principle error.