4FC2

The AVL type 4FC2 is a MicroIFEM signal-conditioning amplifier for combustion (indicating) measurement on engine test beds. The front panel is marked AVL MICROIFEM and COMBI. It has two piezoelectric charge inputs (Q3, Q4) and two multipurpose inputs (CG1/VG1, CG2/VG2), which matches the MicroIFEM combi layout of 2 piezo and 2 multipurpose channels. The type plates show material number BD0329 and a 9.5-36 V DC supply.

In the MicroIFEM family, piezo channels condition cylinder-pressure sensors and piezo accelerometers with drift compensation. Multipurpose channels condition strain-gauge, piezo-resistive, inductive and voltage sensors, such as manifold or rail pressure. Each channel is electrically isolated against ground loops. The 1 HU housing is made to be mounted close to the engine.

On the back are CH1-CH4 BNC signal outputs, RS232 IN/OUT for daisy-chaining, power IN/OUT, a unit-address switch and an X9 connector. Units are set up from a PC with AVL IndiSignal, or by AVL IndiCom when connected to an AVL acquisition system. The 4FC2 is an earlier MicroIFEM generation; AVL's later combi model is the MicroIFEM 4C4 Combi.