22.214.171.124.2 Image shift due to range focus knob. Rotation of the range
focus knob by 40 ± 1° , clockwise and counterclockwise, from the best focus
position at 1500 meters shall not cause the target image to shift more than 3
roils (total spread) relative to an auxiliary telescope at the eyepiece of the
126.96.36.199.3 Effect on diopter setting. The diopter setting shall not
change more than 0.25 diopter, as read on the diopter scale, when the focusing
knob is rotated through the range specified in 188.8.131.52.1.
184.108.40.206.4 Image centering. With an incident line of sight perpendicular
to Datum Plane "D" and the input coupling set at 66° with respect to Datum
Plane "A", the target shall appear centered relative to the eyepiece diaphragm
within 10 mils.
3.12.1 Disengagement of knob locks. The direct force required to disen-
gage the diopter knob and each boresight knob shall be within the limits of
2.0 to 5.0 pounds (lbs.), and shall not exceed 9.0 lbs. at -65° and +150°F.
3.12.2 Torque. The running torque required to rotate the controls listed
helm, through their full excursion of travel, shall be within the limits for
the temperature indicated. The boresight slip scales and the filter lever
shall be manually operable at all of the specified temperatures.
60 to 90
-650 and +150°F
a. Periscope. The periscope assembled in accordance with 3.8a shall
withstand & internal presure of 5 + O.1O pounds per square inch gage (Psig)
for a minimum of 45 minutes with no evidence of leakage.
b. Head and body assembly with shipping covers installed The head
and body assembly, with shippfng covers, shall withstand an internal pressure
of 5 ± O.1O pounds per square inch gage (psig) for a minimum of 45 minutes
with no evidence of leakage.
3.14 Flushing Upon satisfactory completion of flushing requirements of
3.14, the accepted head assembly and body assembly, with shipping covers
installed, shall be flushed with dry nitrogen. The flushing shall continue
until the gaseous mixture bled from the head and body assembly has a dew point
of at lease -25°F. The units shall then be sealed with dry nitrogen to an
internal pressure of 3 psi ± .5 psi.