FIRE CONTROL TEST EQUIPMENT
Section I. OPTICAL TEST INSTRUMENTS
The optical test instruments listed in this section are those most commonly used in the rebuild and inspection of fire control
instruments. The test instruments are usually used in conjunction with test fixtures, V-blocks, and holding devices.
Description. The projector collimator (fig. 10-1) is an optical device similar to an ordinary straight tube
telescope except that it does not have an erecting system. The eyepiece is designed and machined to accommodate a
lamp housing, which has a clamping screw so that it may be secured to the collimator. The lamp housing is equipped with
a lamp assembly which provides illumination for the collimator. The collimator contains a reticle (fig. 10-2). The reticle
pattern is graduated in mils and a 1 mil square at the center is provided so that any adjustment or inspection necessitating
1/2 mil tolerance can be accurately made. Smaller tolerances can be easily estimated. Resolution marks on the reticle
are provided as an aid when checking definition of the instruments optical system. The objective end of the projector
collimator is adjustable and has an objective scale graduated with an infinity mark and four other marks representing 75,
100, 200, and 500 yards, so the objective can be accurately positioned, setting the projector collimator at the correct
Use. The projector collimator serves as a testing target when used with various test fixtures for collimation and
final inspection of fire control sighting instruments. The collimator is also used for checking definition of field-of-view,
parallax, reticle plumb, and reticle accuracy.
Figure 10-1. Project Collimator.