Engine Pressure Ratio (Epr) - GE ADTS542F User Manual

ADTS542F/552F/553F/554F User Manual
End of testing
When testing is complete, use the Aircraft status screen to initiate a descent to ambient ground
pressure at a safe rate. The rate may be increased or decreased if required from within this screen.
To see full parameter details, simply clear the status screen view. It can be recalled at any time. If
working with the ADTS .
When the ADTS displays the status as AT GROUND, it is then safe to disconnect the aircraft Ps and
Pt connections. The ADTS base unit will also show steady green on the rightmost aircraft status
LED when in this state.

3.11 Engine Pressure Ratio (EPR)

The ADTS may be used to check EPR sensors and indicators. Use Ps (static) for INLET pressure and Pt
(Pitot) for OUTLET pressure.
To carry out an EPR check, the display must be showing units of pressure measurement e.g. mbar,
inHg.
Note: Altitude correction applies to EPR values, make sure this correction does not adversely affect
accuracy. The difference in height between the ADTS and the EPR sensor may be different to the altitude
correction previously set for the aircraft instruments.
The EPR function can be operated using one of two methods, as follows:
1. Direct control of Inlet pressure and target EPR value (outlet pressure is auto-set).
2. Direct control of Inlet and Outlet pressure (equivalent EPR aim is auto-set).
The actual method to be used will be specified in the aircraft maintenance manual.
Setting the EPR - method 1
1. On the "Dashboard", select "EPR". The EPR control screen appears.
2. On the EPR control screen, set the toggle control (1) for direct control of Inlet pressure and target
EPR value.
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