for compliance with the resolution requirement of 3.5.1.
4.7.2 .1.2 Spherical power.- The average of the horizontal and vertical
target focus readings obtained in each of the nine areaa, as outlined in
126.96.36.199, shall be between - 0.5 to +0.25 diopters for comPliance with the
spherical power requirement of 3.5.2.
188.8.131.52.3 Astigmatism.- The algebraic difference in focus between the
horizontal and vertical target focus readings obtained in each of the mine
areas, as outlined in 184.108.40.206, shall not exceed .25 diopter for compliance
with the astigmatism requirement of 3.5.3.
220.127.116.11 Light transmission.- Light transmission of the periscope shall
be determined by means of a photometer. Prior to testing for light trans-
mission, full intensity of the light source must be determined. The actual
test is made by inserting the periscope between the light source and the
means provided for picking up the exit ray of the periscope. The actual
light transmitted through the periscope shall be measured by the means pro-
vided. The percent of light transmitted shall conform to the limits speci-
fied in 3.5.4.
4.8 Mirror and window laminations.- The laminations of the mirrors and
windows shall be visually examined for compliance with 3.4.4. The appearance
of any bubbles, blisters, cracks or separations shall be considered evidence
of bond failure.
4.9 Bubbles and inclusions,- The samples of plastic material for the
body shall be inspected for bubbles and inclusions under brilliant illumi-
nation such as is provided with a standard 500 watt lantern slide projector,
or equivalent. The viewing shall be through one of the faces of the blank,
to which a heavy coat of mineral oil has been applied to produce a trans-
parent surface. The blank shall be backed by a dull background such as
black felt or black masking paper during this inspection. The distribution
and size of bubbles and inclusions shall conform to 3.6 and Table I, Sec-
3.10 Lint.- The test for lint shall be performed on the samples
of plastic material at the same time that the test for bubbles and inclusions,
4.9, is being perfomed. The length of the lint particles shall conform to
the requirements of 3.6.1. The total projected area of any lint particles
shall be computed as stated in 3.6.1 and added to the total area found in
4.9 for conformance with 3.6.1
4.11 Qualification tests.
4.11.1 Qualification tests shall consist of all tests specified herein
using the six items submitted in accordance with 4.2. These tests shall be
performed at Frankford Arsenal, Philadelphia, Pa., unless otherwise specified
by the contracting officer. Upon successful completion of all tests in
Tables I and II, the periscopes shall be subjected to the tests in 4.11.2
for compliance with 3.4.1.