ENGINE VIBRATION SIGNAL CONDITIONER
Location (IPC 77-31-03-01)
Item: 40
Part Number: 6670M2227
Station: 322.9
Zone: 205
Rack: E1-2
Ata: 77
Sub-Ata: 77-31-00
ENGINE INDICATING
Description (AMM 77-31-00)
The AVM signal conditioner processes inputs from vibration sensors, N1 and N2 speed sensors. The monitor unit is programmed to determine the N1 and N2 rotor vibration from the fan and core sensors. The unit is a microprocessor with BITE, self-test and flight data history functions.
(1) AIRPLANES WITH A S332T304 AVM
Have a linear scale for flight compartment indication. The scale from 0 - 5 scalar units can be compared to a scale of 0 - 10 mils DA (Double Amplitude) of vibration.
(2) AIRPLANES WITH A S360N021-100, -102, -113, -114, -201, -202, -203 OR
-213 AVM
a) This AVM has a bi-linear scale for flight compartment indication. The scale from 0 - 2.5 units compares to a scale of 0 - 5 mils DA (Double Amplitude) of vibration. The scale from 2.5 - 5 units compares to 5 - 20 mils DA of vibration.
b) This AVM has a 2 minute time delay at the engine start, so that the transient engine start up vibration is not recorded on the flight history data.
