What Are Autocollimators?

A collimator is a precision angle measuring instrument, consisting of two parts, a collimator and a telescope, as shown in the overview diagram. ^[1] With the development of technology, according to different angle measurement principles, collimators can be divided into optical collimators and laser collimators; the structure has a collimator and a telescope integrated autocollimator.

The structure is shown in the overview diagram. The telescope is equipped with a crosshair, and the general magnification is 24 to 60 times. The main lens (objective lens 1) is fixed, and the focusing lens 2 is movable

Place the parallel light tube fixed on the special bridge plate on the plane to be measured, adjust the telescope on the adjustable bracket to align the sight line with the cross line of the parallel light tube, and then measure the straightness by the "pitch method" Measure straightness. ^[1]

An autocollimator is also called a micrometer autocollimator, which essentially combines the telescope and collimator of the collimator into one. Its optical system reflects twice from the objective lens to the reticle through the reflector, which greatly shortens the length of the instrument. At the same time, the optical axis of the objective lens and the optical axis of the eyepiece form 90 ° with each other, which is convenient to use. ^[1]

Since the advent of laser, because of its advantages such as energy concentration, good directivity, and good coherence, lasers have become more and more widely used in collimation measurement. The laser collimation measurement instrument developed at home and abroad has not only the intuitiveness and simplicity of wire drawing, but also the high precision of the optical collimator, and it can also realize full-automatic measurement. Laser collimation measurement technology provides an ideal method for straightness measurement in many fields. ^[2]