Epr
 

Can someone please explain the use of EPR to a lowly turboprop driver? I understand it stands for Engine Pressure Ratio but i read about using it as another tool like airspeed etc. Ie you can set a certain EPR for different stages of flight to get a specific performance. Can someone enlighten me please?

It's a measure of power setting. A certain EPR setting for the prevailing conditions (weight,altitude and temperature) will result in a certain speed akin to an RPM setting. Not a substitute for the ASI though.

Pratt & Whitney and Rolls Royce engines use EPR as the primary indication of thrust, GE use N1 RPM.