Aeroflex Operation Manual
PSD60-2R – REV 1 – AUGUST 24, 2011 – PAGE 2-2
2.3 CAPACITANCE SIMULATION
CAUTION: Some procedures may specify that the test set should not be connected to airframe ground when
simulating capacitance. This is because some test sets connect airframe ground and shield
together, thereby grounding the shield at a point other than the "Single-Point" ground. This test
set isolates case and shield ground in the simulate mode, so this precaution is not necessary.
The test set should be connected to airframe ground for all tests.
1. Connect CHASSIS jack (J7) to Airframe.
2. Turn power ON, select the desired LO-Z frequency, and allow three minutes for test set to
stabilize.
3. Check battery condition, if "LO BAT" is displayed on the display replace batteries.
4. Turn the FUNCTION SELECT switch (A3S1) to MEASURE INT.
5. Connect INDICATOR LO-Z, HI-Z, and COMP connectors (P1, J2, and P3) to the aircraft interface
with the appropriate interface cables. Assure that no cables are connected to P4, J5, and P6.
6. Turn the MEGGER SELECT switch (A3S2) to TU.
7. Adjust TU decade (S6, S7, and S8) below desired capacitance value.
8. Adjust TU FINE knob (C1) to desired capacitance value.
9. Turn the MEGGER SELECT switch (A3S2) to COMP and adjust COMP decade (S9 and S10)
and COMP FINE knob (C2) to desired capacitance value.
10. Turn FUNCTION SELECT switch (A3S1) to SIM TU & COMP.
NOTE: Connecting test harnesses and interface boxes should not add capacitance to the system.
However, if the cable is suspect, connect only the cable to P4, J5, and P6 and read its
capacitance per measurement procedure. If cable capacitance is less than 1 pF above displayed
reading with no cables connected to test set, subtract its capacitance from the amount being
simulated. If over 1 pF, repair cable; shields are probably improperly terminated.
NOTE: When simulating tank unit only, as in the case of an uncompensated system, FUNCTION
SELECT switch (A3S1) should be in the SIM TU ONLY position.
NOTE: The AIRCRAFT ONLY position disconnects both simulators. This is used when delta values are
simulated and actual dry tanks are used for empty.
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