Honeywell Vibrex 2000 User Manual page 193

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An internal EV2K+ "chart" provides sensitivity and phase angle
coefficients used to perform balance solution computations. As
long as a measurement is gathered in all the matching conditions
as stated above, the internal charts should provide accurate
solutions.
A good balance for a given regime and change type should
normally be reached in two sets of adjustments (three or less
flights). All of the acquisition and setup conditions as well as
component mechanical condition should be verified if it is not.
Auto-correction may be used in cases where the above
conditions cannot be satisfied. These can be special or custom
installations, components that don't exactly match the charts
because of physical or statistical differences, or even to create
new charts. Auto-correction is performed by checking actual
versus predicted "movelines" and applying a correction factor.
At least two measurements must be acquired to compute a
moveline.
The EV2K+ uses an "auto-correct once with existing
adjustments" algorithm for helicopter balance. Note that this is
similar but slightly different from the Propeller Balance "remove
all weights and auto-correct once" algorithm. Auto-correction
will be performed if all of the following conditions are met:
1. Auto-correction is turned ON. It is normally defaulted to
OFF.
2. Auto-correction has not already been performed for this
balance session.
3. A moveline has been computed from one run to the next and
the moveline is:
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Change (adjustment) type
a. More than 0.2 IPS in length,
Chapter 5 – General Operation
13841 Rev A
177