56-101-01501_01502 Revision D
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3. RECERTIFICATION
A. The Test Set has a one-year recertification requirement. Maintenance required by this
unit must be performed by qualified technicians in a shop equipped with the necessary
tooling and resources. Contact Barfield for Maintenance and Calibration requirements.
B. At the conclusion of the power up initialization the MAIN MENU screen provides the next
Calibration due date in the format of Month/Day/Year.
CAUTION:
Recertification by a calibration/repair shop
not
possessing the necessary
technical knowledge, documentation, special test equipment, tooling and
standards will adversely affect the accuracy/capability of the DFQ40K for
testing the aircraft.
C. The process of Calibration requires that the Unit Under Test (UUT) be compared to
Certified Traceable Standards having an accuracy at least 4 times better than the UUT.
Adjustments are made to the UUT in order to align the UUT to the exact values of the
Standards so that the errors at all required test points are zeroed out.
Conducting a simple Bench Check
(*)
(Verification) is quite different to the calibration
process as no adjustments are made to the UUT; so long as test points fall within the
specified allowable tolerances the unit is said to pass. This method disregards the
stability specification for the unit since any number of test increments could fall just
within the maximum allowable error. This may result in units being returned to service
and drifting out of tolerance a few months later.
Note
(*)
:
Barfield does NOT consider a Bench Check (Verification) process to be a
suitable or responsible alternative to an actual calibration/realignment of the
measurement system’s linearity accuracy. Barfield does not endorse this
practice for obvious reasons as the test set cannot be guaranteed to meet its
designed accuracy specifications and especially so under varying operating
temperature situations.
4. TEST SET EQUIVALENT
The Barfield DFQ40K, Fuel Quantity Test Set, is a suitable substitute for the Barfield 190F,
290F, 2548F, 2548G, 2548GA, 2548H, 2624F, 2624G, Model 8000 and AC2K Fuel Quantity
Test Sets for all aircraft applications.