GE AquaTrans AT868, User Manual

Page: 70 / 158

Calibration 4-3
September 2004
Testing Output Linearity
1.
Press
[ESC]
,
[ENTER]
,
[ESC]
. The meter enters the user program.
2.
Press [
X
] until
CALIB
appears and press
[ENTER]
.
3.
Press [
X
] until
SLOT0
appears and press
[ENTER]
.
4.
Press [
X
] until
A
or
C
appears and press
[ENTER]
.
5.
Press [
X
] to select
Test
and press
[ENTER]
.
6.
Under
% Full Scale
enter
50.00
by using the arrow keys. Press
[
W
]
and [
X
] to move the cursor to desired location and press
[
S
]
and
[
T
]
to increase or decrease the number and press
[ENTER]
.
7.
Check the ammeter reading. Table 4-1 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.
Note:
If the linearity test readings are not with 5
µ
A of the values
listed in Table 4-1, 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.
8.
Repeat Step 2 but enter a different output (0-100%). Check the
ammeter reading at this setting and press
[ENTER]
when done.
Procedure Options
After completing the above steps, the meter returns to the
ANALOG
OUTPUT
window. Do one of the following:
•
To perform another programming function, refer to Appendix
A,
Menu Maps , to navigate to the desired menu.
•
To leave the User Program , press
[ESC]
three times.
Table 4-1: 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