Resetting “USED”
Every time you inform the EDM-760/790 that the aircraft is refueled, the
amount of fuel
used
is set to zero, unless the instrument is programmed to
accumulate. The display of fuel
used
pertains only to the fuel used since
the last time you informed the EDM-760/790 that the aircraft was
refueled.
To reset to zero the amount of fuel
used
at any point in time, manually
step to display
USD
and hold both buttons for five seconds until the
display shows .
0 USD
.
Fuel Management
Without a means of measuring fuel flow, you must rely on the aircraft
fuel gauges or total time of flight. Aircraft fuel gauges are notoriously
inaccurate (they are only required by the FAA to read accurately when
displaying
empty)
. And measuring time of flight is only an approximation,
and assumes a constant fuel flow rate for each phase of flight.
The EDM-760/790 Fuel Flow Option uses a small turbine transducer that
measures the fuel flowing into each engine. Higher fuel flow causes the
transducer turbine to rotate faster which generates a faster pulse rate.
Because the transducer turbine generates thousands of pulses per gallon of
fuel, it can measure with high resolution the amount of fuel that the engine
has consumed. Prior to engine start you inform the EDM-760/790 Fuel
Flow Option of the known quantity of fuel aboard, and it will keep track
of all fuel consumed.
For fuel calculations to be accurate, it is
imperative that you inform the EDM-760/790 of the correct
amount of fuel aboard the aircraft. Do not rely on fuel flow
instruments to determine fuel levels in tanks. Refer to original
fuel flow instrumentation for primary information
For Your Safe Flight
Page 33
Summary of Contents for EDM-760 TWIN
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