GE DigitalFlow GC868, Service Manual

Page: 11 / 75

April 2008
1-4 Calibration
Calibrating the High End
of the Output Range
1. Press
[F2]
to calibrate the high end of the output range.
2. Press
[F1]
or
[F2]
to adjust the ammeter reading
UP
or
DOWN
, until
a 20 mA reading is achieved. If you press
[F3], Numer,
enter a
numeric value for the calibration point and press
[ENT].
Note:
If the ammeter reading cannot be adjusted within 5.0
μ
A of the
20 mA setting, contact the factory for assistance.
3. Press
[F4]
to
STORE
the setting, or press
Æ
and
[F1]
to
ABORT
the
calibration.
Note:
Skip the next section if the linearity test will not be performed
at this time. Proceed to
Procedure Options on the next page.
Testing the Analog Output
Linearity
Note:
If you exited this menu and are returning, follow steps 1
through 3 in
Accessing the Calibration Menu
on page 1-3.
1. Press
[F3]
to
TEST
the linearity of the currently selected analog
output.
2. Check the ammeter reading at the 50% output level.
3. Then, enter a different output level (0-100%) and press
[ENT].
4. Check the ammeter reading at this setting and press
[ENT]
when
done.
Table 1-1 on page 1-5 lists the expected ammeter readings at various
% Full Scale settings, for both 4-20 mA and 0-20 mA scales. Refer to
this table to verify the accuracy of the ammeter readings taken above.