TM-9-1240-400-34&P Technical Manual for M109 Telescopes and Mounts Download
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TM 9-1240-400-34&P 2-5. CATEGORIES OF INSPECTION (CONT) Table 2-1. INITIAL INSPECTION-M115 PANORAMIC TELESCOPE (CONT) ITEM ITEM T0 NO. BE INSPECTED PROCEDURE ACCURACY NOTE: For the following inspections mount telescope on EVALUATION preset Azimuth Testing Fixture. Refer to page 2-58 for setup instructions. 21 Eyepiece Focus Eyepiece focus shall be tested with aid of calibrated dioptometer adjusted for best focus of dioptometer reticle. Position dioptometer at telescope eyepiece. Telescope reticle shall be in best focus within -0.75 to -1.0 diopter, as measured on dioptometer scale. - Parallax Parallax in center of the field (geometric center of the reticle) shall not exceed 0.15 mil while viewing a target set at 130 + 10 m For purpose of this test, thickness of telescope reticle line may be considered as equal to 0.10 mil. - Definition The telescope shall produce sharp and clear image at center field of view when checked with the aid of dioptometer. - Image Tilt Position pre-plumbed collimator telescope, at eye- piece of M115 panoramic telescope, so that the optical axes of the two telescopes lie in parallel planes. When line of sight is directed through the auxiliary telescope and M115 panoramic telescope to target, image of vertical reticle line shall be within 1 degree, as measured on projector collimator test reticle. Refer to TM 9-254. -- Parallelism of Reticle and Image Vertical reticle line shall be parallel to image of a plumb line, within 30 minutes of arc, at any deflec- tion setting through at least 2 full revolutions of head Refer to TM 9-254. 2-6