L-1011 Engine: Vibration Indication

To measure the RB.211 engine vibration several sensors are used to feed the indicator systems on the L-1011.

Vibration Pickups

• Two pickups utilized
• Both pickups located on top of IP compressor case
• The pickups are identified as A and B
• The pickups provide signals for the signal conditioner unit

Signal Conditioner

• Contains rectifiers and filters for processing signals from pickups. 
• Contains level detector which operates warning light on respective engine indicator
• Provides three frequency bands that correspond to vibration frequencies of the N1, N2 and N3 stages.