GE DigitalFlow DF968, Руководство по обслуживанию

Страница: 12 / 78

March 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 the
numeric value and press
[ENT]
.
3. Press
[F4]
to
STORE
the setting or press [
→]
and
[F1]
to
ABORT
the
calibration.
Note:
If the ammeter reading cannot be adjusted within 5.0
μ
A of the
20 mA setting, contact the factory for assistance.
Testing the Analog Output
Linearity
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. Press
[ENT]
when done.
Table 1-1 below 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.
If the linearity test readings are not within 5
μ
A of the values listed in
Table 1-1 above, check the accuracy and wiring of the ammeter.
Then, repeat the low and high end calibrations. If the analog output
still does not pass the linearity test, contact the factory for assistance.
Table 1-1: Expected Ammeter Readings
% Full Scale 4-20 mA Scale* 0-20 mA Scale*
0% 4.000 0.000
10% 5.600 2.000
20% 7.200 4.000
30% 8.800 6.000
40% 10.400 8.000
50% 12.000 10.000
60% 13.600 12.000
70% 15.200 14.000
80% 16.800 16.000
90% 18.400 18.000
100% 20.000 20.000
* All ammeter readings should be ±0.005 mA