Reference Manual
748384-C
September 2003
Rosemount Analytical Inc. A Division of Emerson Process Management
Introduction 1-45
NGA2000 Reference
1-25 AUTOCALIBRATION MODULES
There are two types of Autocal modules avail-
able, a single analyzer module and a
four-analyzer module. The former provides
greater flexibility when dealing with a single
analyzer system, but the latter is more eco-
nomical in multiple analyzer systems. The sin-
gle channel module also provides an analog
output that is identical to the one in the Analog
Alarm I/O Module, but cannot automatically
change ranges.
These modules are physically identical to the
Analog Alarm I/O Module. The only difference
is the software contained in the ROM.
a. Troubleshooting
I press Zero and the analyzer zeros off
the sample…
The analyzer zero and span controls are not
linked to the Autocalibration module. If you
want to do an automatic calibration, enter
the menus, enter
Expert controls and setup
and enter
Auxiliary module controls...,
se-
lect the
Autocalibration module
and press
"START"'. Simply to do an automatic zero
you have to select the
Manual calibration
function in this screen, select
zero gas
and
the
zero operation
, and press "START".
I set a start time but the module didn't do
anything…
Verify the system clock is set correctly, and
verify that the start day and time you chose
is in the future from the time you set it.
Then wait until that time.
I want to synchronize several analyzers
to calibrate at once…
You should use the system Autocalibration
module for this. You can only synchronize
the zero start times between Autocalibration
modules.
I put zero and span gases into the ana-
lyzer but the analyzers won’t calibrate…
Verify that you have set them to calibrate,
not QC check in both the zero and span gas
valves, and also the general parameters.
Verify that the gases are correct, and the
analyzers are not trying to correct so much
that their calibration limit checking stops
them. Also verify that your dwell times are
long enough that the zero and span read-
ings are reached.
The analyzer does funny things on span,
I can't figure it out…
If the analyzer changes range due to the
Autocalibration module telling it to do so,
the reading will possibly change, particularly
if the ranges are not themselves all cali-
brated. Verify that all ranges are either cali-
brated or that the system is setup to work
on one range only If this is the case, it is
safest to set all ranges to be the same, then
it won't matter if you have a range change.
b.
Differences Between The System
Autocalibration Module And The
Single Autocalibration Module
The System Autocal Module is identical
physically to the Single Autocal Module.
However it does. not provide an analog
output. It can zero up to four analyzer
modules simultaneously, and span any of
them on any range on each of its four span
gas valves.
Set it up in the same way as for the single
Autocalibration module, except that for each
span valve you have to choose not only
which analyzer but also which range to
span on.
The module's menus refer to Analyzer 1,
Analyzer 2, Analyzer 3 and Analyzer 4.
There is a menu available which will let you
tell which analyzer is which.
c.
Use Of The System Autocalibration
Module And The Single
Autocalibration Module
Use the System Autocal Module when you
want to synchronize calibrations of up to
four analyzers in a system and you are us-
ing a common sample system for them all.
Use the single Autocalibration module when
you have just one analyzer, or when you
have separate zero and span gas paths into
