AFG/AFTI Mk 4
Service and Repair Manual
Number 022-614
Issue Number: 09
Page 7 of 47
appear. This can be used as an indication of overload and the current condition of
the loadcell.
Press the
ESC
key twice to revert to normal display.
8) Check the loadcell offset: Software post V1.01
Place the gauge horizontally on a flat level surface. With the gauge switched on, hold
down the
MENU
key until the menu appears. Press the
MENU
key again to show
menu page 2. Using up/down buttons select “
CALIBRATION
” and press
ENTER
key. The display will show 0000. Press
ENTER
four times (to enter 0000 as the
password), a screen displaying the current offset of the load cell as a percentage,
and any overloads in tension and compression.
Press
ESC
twice to revert to normal display
If the displayed offset is between 5 and 10%, recalibration is recommended.
If the displayed offset is greater than 10%, a replacement loadcell may be required.
These values are given as an indication only
– the need for calibration/repair may
vary according to the individual characteristics of the sensor.
To check the load cell mV offset:
Access the load cell connection with the PCB by removing the front case. Section 6
instructions 1
– 7, do not unplug the front panel from the PCB.
With both halves of the gauge connected and the gauge switched on, measure the
load cell excitation voltage between pins 1 and 4, this should be 5V. Then measure
the load cells return signal between pins 2 & 3 (ideally this should read 0.0 mV.)
Once a reading on the voltmeter has been obtained, apply a small force to the load
cell in both directions and ensure the voltmeter display alters in both directions.
Care must be taken whilst applying any force to the load cell
,
