TM 55-4920-399-13&P
Section III. INSPECTIONS AND SERVICING
and efficiently perform its assigned mission if the steps
3-7. Daily Inspection. Daily inspections shall include
visual inspection and a brief operational check, as
ter 2 are successfully carried out.
follows:
3-10. Display Lighting Check. Turn the MODE SE-
3-8. Visual Inspections. Make sure there is no obvi-
LECT switch to the ME AS INT position. Turn the
ous dirt, dust, moisture, or other visible contaminants
T/U/COMP switch to T/U function and the RANGE
on or in the test set.
switch to LO range.
3-9. Operational Checkout. This checkout can be per-
3-11. Tank Unit Simulator. Set TANK UNIT SIMU-
formed following the last operation of the day or preced-
LATOR to any figure over 1000 pf. The CAPACI-
ing the next days operation. The Test Set can safely
TANCE -Pf display should flash all four eights (8888).
Section IV. PREVENTIVE MAINTENANCE
c. The Test Set is designed to be water-tight and air-
3-12. Cleaning. If cleaning of the Test Set is required,
tight, therefore it should not require internal cleaning.
use a lintless cloth moistened with a mild soap and wa-
ter solution to clean the carrying case, front panel, and
cable assemblies.
d. However, occasional internal air drying maybe re-
quired, using warm air or compressed air at 15 psi or
less. Refer to Troubleshooting Section.
a. A soft bristle brush moistened with a mild soap
and water solution may be used to remove stubborn
3-13. Lubrication. Not required.
deposits.
3-14. Extreme Environmental Maintenance. As in-
b. Resinous or oily deposits may be removed using
dicated on Table 1-1, the operating temperature range
a lintless cloth or a soft brush moistened with methyl-
of the Test Set is -40C to + 55C and any malfunction
ethyl-keytone (item 2, Table 1-4).
that occurs outside this temperature range will be cor-
rected when the Test Set is operated within this de-
NOTE
sign temperature range.
Do not leave any cleaning fluid residue.
Section V. OPERATIONAL CHECKOUT
3-15. Performance Checks. Refer to paragraphs 3-7
through 3-10.
cause/corrective action data. Refer to Fig. 4-8 for the
wiring diagram and Table 3-2 for the wire list.
Table 3-1. Troubleshooting
Trouble
Probable Cause
Corrective Action
Display shows proper
Excessive moisture inside
Remove panel and dry with low
number but is unsteady,
pressure warm or compressed air.
Test Set.
Failure Al, A3, A4, or
Return to AVIM level of
Display jumps randomly.
Maintenance.
A7 board.
Change 1
3-2
