188.8.131.52 Objective focusing range.
184.108.40.206.1 Daylight.- This test shall be performed subsequent to the
test in 220.127.116.11. A dial indicator, graduated in .001 of an inch, mounted
on an appropriate stand, a supporting medium capable of receiving the dial
indicator as well as the body assembly to be tested and the screwdriver
specified in 18.104.22.168.1 shall be utilized for this test. With the daylight
body removed from the periscope and firmly secured on the supporting medium,
position the dial indicator so that its contact point touches the face of
the movable objective tube of the daylight body and set the dial to read
ZerO with the indicating hand.
Back off the locking screw of Housing
11727432 a minimum of two full revolutions from its locked position. Start-
ing from the zero reading of the dial indicator, rotate the eccentric until
the objective assembly has traveled the minimum distance specified in 22.214.171.124,
as measured on the dial indicator. Return the indicating hand of the dial
indicator to zero by means of the eccentric and repeat this travel in the
opposite direction. There shall be sufficient travel in each direction to
meet the minimum requirements specified in 126.96.36.199, as measured on the dial
indicator. Upon completion of this test, reinstall the daylight body in
periscope and repeat the parallax adjustment procedure specified in 188.8.131.52.1.
The daylight body shall then be subjected to the test in 184.108.40.206.
220.127.116.11.2 Passive.- This portion of the test shall be performed with
10" collimator adjusted for 50 meters. With the diopter ring adjusted for
best focus of the phosphor grain on the screen of the image tube, rotate
focusing ring of the elbow assembly for best focus of target image to de-
termine compliance with 18.104.22.168. Upon satisfactory completion of this por-
tion of the test, the 10" collimator shall be readjusted for infinity to
determine compliance with the 3,000 meters specified in 22.214.171.124. With the
diopter ring adjusted for best focus of the phosphor grain on the screen
of the Image tube, again rotate the focusing ring of the elbow assembly for
best focus of the target image to determine overall compliance with 126.96.36.199.
188.8.131.52 Resolution - daylight.- The daylight optical system of the
periscope shall be inspected for resolution utilizing a calibrated diop-
toxmeter with a manification of at least three power. Set the dioptometer
objective scale to zero and adjust the dioptometer eyepiece for best focus
of the dioptometer reticle. Set the diopter adjustment knob of the peri-
scope daylight eyepiece to indicate zero diopter. Position the dioptometer
at the periscope daylight eyepiece. While viewing through the dioptometer,
adjust the objective scale of the dioptometer for best focus of the resolu-
tion pattern appearing in the fourth quadrant of the target reticle located
in the 10" Collimator (Ref. Dwg. F11738140 Test Set-up, Periscope). Any
change in diopter readings by adjustment of the dioptometer objective scale
to obtain the detectable line structure and proper line count in all four
meridians shall be recorded as measured on the dioptometer objective scale.
The difference between the recorded readings for any two meridians shall not
exceed the value specified in 184.108.40.206.