TM 11-6720-239-35
(6) Carefully inspect the light seals between
g. Plug in and operate the flashgun. Use a G. E.
the shutter and the light source box, and between
No. EEK test bulb or a regular M-3 flashbulb.
the camera back and the phototube/camera
Check to see that test bulb fires.
adapter.
h. Perform the bellows light leak test in a light
tight room; use a light leak probe and carefully
b. Test Procedures. For each test setting in step
inspect the bellows for holes.
c, proceed as follows:
i. Insert a film pack into the camera and take
(1) Make the necessary light source and
several pictures. Carefully examine the prints for
camera settings.
defects.
(2) Cock and trip the shutter.
(3) Read the oscilloscope and record the re-
sults.
c. Test Settings.
a. Preliminary Connections.
Correct oscilloscepe
(1) Set the L/D control to normal and focus
indication
Camera
settings
Light source setting
for infinity.
10.5ms to 16 ms
150 dull
50 cdls/ft2
145ms to 98ms
(2) Mount the camera on the test stand with
150 bright
800 cdls/ft2
0.63ms to 1.2ms
150 dull
the lens and photocell flush against the corre-
22ms to 35ms
5 0 c d l s / f t2
75 dull
sponding openings in the light source box.
10.5ms to 20ms
3.125cdls/ft 2
3000 dull
(3) Open the back of the camera and insert
d. Performance Standards for Camera Shut-
the phototube/camera adapter; make sure that
ters. The camera shutter must perform within the
the phototube is installed and connected as shown.
indicated limits at every test setting. If any oscil-
(4) Apply power to the oscilloscope, 90-volt
loscope indication is outside the required limits,
power supply, and 110-vac variable transformer.
the camera is not acceptable for reissue.
AllOW equipment to warm up for approximately
10 minutes.
(5) Set the oscilloscope controls as follows:
(a) Set UPPER BEAM control to AC-DC.
a. Inspect for obvious
damage to optical compo-
(b) Set SYNC control to UPPER DC.
nents.
(c) Set MODE SELECT control to NOR-
b. Focus on an object
about a mile away. Check
MAL.
to see that the movable
image is superimposed on
(d) Set SENSITIVITY control to 4 CM.
the fixed image.
NOTE
c. Focus on an object
3 to 4 feet away. Check
Time is measured from open to
to see that the movable
image is superimposed on
closed shutter.
the fixed image.
