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TM 9-254
10-10.
Lens Bench - Continued
Figure 10-11. Lens Bench
(1)
The lens bench contains three main elements, the collimator telescope, the nodal slide, and the
observing microscope, together with the bed on which they are mounted. The collimator and base of
nodal slide are permanently mounted on the bench, while the microscope is mounted on ways which are
attached to the bench. These are accurately machined and alined, along which the microscope may be
moved. The bench is equipped with a graduated scale, usually placed beneath one of the ways, while
the microscope is equipped with an indicator and vernier scale so that its position can be determined to
within 0.001 inch.
(2)
The collimator telescope is arranged to fulfill two functions. One is to provide a suitable source of light,
usually of parallel rays, and the other to provide a proper target.
(3)
The nodal slide carries an adjustable chuck for mounting the lens under observation. The chuck is
supported on the slide in such a way that it can be rotated on a vertical axis, and also can be moved
longitudinally in a pair of short ways.
10-10
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