of 0.2 psig. The interior atmosphere of the accepted telescope
shall contain nitrogen having a dew point of at least as low as
3.6 Orientaiton. - The telescope shall meet the requirements
of 3.7 with the tapered holes vertical, the level vial bubble
centered, the mechanical cant index line indicating zero, and
the eyepiece arm horizontal.
3.7.1 Collimation. - The line of sight through the boresight
point of the reticle shall be 20 mils ± 1.0 mil above the
geometric axis and within 1.0 mil of a plumb line passing
through the geometric axis.
3.7.2 Parallelism of reticle and image. - The horizontal
reticle line nearest the goemetric axis of the reticle shall be
parallel to a horizontal target line within thirty minutes of
3.4.3 Reticle accuracy. - The angular value between the
zero range mark and the maximum range mark (in the finished
telescope) shall be as indicated on the reticle drawing within
3.7.4 Eyepiece focus. - The eyepiece focus shall be fixed
between the limits of -0.75 and -1.0 diopter.
3.7.5 Resolution. - The resolution at the optical axis
shall be 12 seconds of arc or less.
3.7.6 Parallax. - Parallax at the geometric axis shall not
exceed 0.15 mil when viewing a target at 600 meters + 25 meters.
3.8.1 Level vial. - The lamp for level vial illumination,
when energized with 18 VDC and 28 VDC, shall provide sufficient
illumination at each voltage for the level vial markings to be
clearly defined when observed in a darkened area.
3.8.2 Reticle. - The lamp for reticle illumination, when
energized with 19 VDC and then 28 VDC, shall provide sufficient
illumination at each voltage for the reticle markings to be
clearly defined when observed in a darkened area. Rotation of
the rheostat knob shall cause a change in illumination of the