AMMONIA User Manual
AMMONIA_User 9/09
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6
4.2 4-20mA Configuration
To calibrate, view or modify
a 4-20mA output
key
UP
or
DOWN
to the target output
and press
ENTER
then
UP
.
Key
ENTER
@
Configure
.
The 4-20mA current output is in
Manual
mode
The current mA level is fixed at the user set level.
Selecting
Auto
controls the current based on the value
of a sensor and the 4mA and 20mA setpoints.
Trim Zero
adjusts the 4mA level.
Put a mA meter is series with the loop current and
key
ENTER
and
UP
or
DOWN
to adjust.
Trim Span
adjusts the 20mA level.
Put a mA meter is series with the loop current and
key
ENTER
and
UP
or
DOWN
to adjust.
4-20mA outputs may be
Interlocked
When the interlock is
ON
the current is
4.00mA
,
0%
key
ENTER
and
UP
or
DOWN
to select an interlock.
Configure
Setpoints
4-20mAOutput_D
4.00mA 0.0%
D
and
Return to Auto
Yes
Trim Zero
9
Trim Span
950
Interlocked
none
Calibrate - Interlock
Sidebar:
Calibrate:
Trim Zero
and
Trim span
places the current loop into
Manual
mode and
then adjusts the zero, 4mA or span, 20mA level.
Set your digital voltmeter to measure mA and install it in
series
with the current loop wiring.
(
Series:
Disconnect one 4-20mA wire from the Analyzer terminal.
Connect the wire to the DVM ‘-‘ or Common and connect the DVM ‘+’ to the wiring terminal)
If
UP
or
DOWN
stops changing the measured current it’s because
you’ve hit the limits of loop adjustment.
Resolution:
The nominal resolution of the current loop is 0.1%.
Example:
If 4mA = 0uS and 20mA = 1000uS the current loop has 1uS resolution.
If 4mA = 0uS and 20mA = 10000uS, the current loop has 10uS resolution.