Shutter Assembly Operational Test

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-

4-5. Shutter Assembly Operational Test

sults.

(fig. 4-1)

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.

4-6. Finder Assembly Operational Test

(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

3½ to 4 feet away. Check

Time is measured from ½ open to ½

to see that the movable

image is superimposed on

closed shutter.

the fixed image.

4-2