TM 11-6625-3081-23
2-14. MODULE DESCRIPTIONS (cont)
2-14
b. DAYSIDE TEST BENCH 2A1 (cont)
Input Code
OSADAS (cont)
PMTLED
Description
The operator closes the OSA door and the shutter is programmed
to open.
The shutter status is checked.
‘ If the shutter remains closed, a prompt Is displayed.
Effectivity:
Used with E/O bench equipped with optical signal
analyzer only.
This module tests photomultiplier bracket assembly 2A1A1A7
filter and bracket assembly 2A1A1A14 photomultiplier tube (PMT)
temperature, and ability to detect light energy.
If an error is detected during any of the following checks, a
prompt is displayed at the completion of the tests.
The PMT cooler is checked by reading the OSA temperature sensors
for 5.0° to 15.0°C.
The OSA PMT is turned on and after a
15-second delay, the PMT high voltage test point is checked for
-3.0 to -5.5 vdc.
The operator is then prompted to connect the
1-250 illuminator to the adapter on the OSA assembly door 2A1A1
and adjust the illuminator for a voltage of 7.80 to 8.20 volts.
The PMT level is then checked for each of 6 loads. PMT test 3
is selected and PMT output checked for 7.80 to 8.20 vdc. PMT
test 3 with filter is selected and PMT output is checked for
0.72 to 0.88 vdc.
PMT test 4 with filter is selected and PMT
output is checked for 7.00 to 9.00 vdc. PMT test 2 is selected
and PMT output is checked for 0.72 to 0.88 vdc. PMT test 1 iS
selected and PMT output is checked for 0.04 to 0.12 vdc. PMT
test 5 is selected and PMT output checked for 0.04 to 0.12 vdc.
PMT test 6 is selected and PMT output is checked for 0.72 to
0.88 vdc.
PMT test 6 with low impedance is selected and PMT
output is checked for -0.04 to 0.04 vdc.
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