ENGINE REVOLUTION COUNTER (REV COUNTER)
This gauge shows the engine speed in revolutions per minute. The range is normally between 
0 and 2700 r.p.m. The cruise setting is normally around 2200 r.p.m.
When the aircraft is fitted with a fixed pitch propeller, as is the case with this PA28 and many other light aircraft, the rev. counter gives a good indication of engine output power. When checking the engine performance before take off, the rev. counter is also monitored to check that the ignition system and carburettor heat system, are both working satisfactorily.