J.P. Instruments EDM 900 Pilots Guide - Manual (Page 43)

For Your Safe Flight Page 43
Fuel Flow K factor
The K factor is shown on the fuel flow transducer as a hand written four-
digit number, which represents the number of pulses per tenth gallon of
fuel flow. Before installing the transducer, record its K factor here
_________. The EDM stores the K Factor in the form 29.12, i.e. if the
transducer K factor is 2912, you would enter 29.12 in the EDM’s K factor
field.
Fine Tuning the K Factor
The K factor shown on the fuel flow transducer does not take into
account your aircraft’s particular installation. Fuel hose diameters and
lengths, elbows, fittings and routing can cause the true K factor to be
different from that shown on the fuel flow transducer.
You must use the following procedure to fine tune the K factor.
1. Make at least three flights of about two to three hours each. Note
the actual fuel used (as determined by topping the tanks) and the
EDM calculation of the fuel consumed for each flight = USD.
Flight
Fuel USED shown by EDM
(total tank - REM) Actual fuel used by topping
tanks
1
2
3
Total  
2. Total  the EDM fuel used and  the actual fuel used.
3. Record the current K factor here ____________________
and in the table below.
4. Calculate the New K Factor as follows:
New K Factor = ( EDM fuel used) x (Current K factor)
( actual fuel used)
New K Factor = (  ) x (  )
(

)
Every time you fine tune the K factor, record the measurements
here:
 EDM  actual  Current New K Pilot’s