AMI Analyzer Manual
Installation and Operation
••••
9
Change Output Range
Press the OUTPUT RANGE button for a second and let go. While the output range value is displayed (you have
approximately three seconds), press the UP or DOWN arrow buttons to change it. The output range will change to
whatever you want. Simply leave it or select another function and the range will be stored and the system updated.
You will note that if this results in an alarm change, the alarms will change as soon as the unit starts showing the
reading again. If the output range does not change, the security level must be set to full or span only security. In this
case change the security level with the laptop and the AMI User Interface program.
Alarm Set Points
The alarm set points can be viewed and changed from the front panel.
View Alarm Set Points
Press either of the ALARM SET POINT buttons and let go. The alarm set point will be displayed for about 3 seconds,
and the then the display will revert to the oxygen reading. The set point shown relates to the current output range. If
you change the output range, the alarm set point will change to a new value which is the same percentage of the new
output range. For example, if the output range is 100ppm, you can set an alarm set point to be half way up, i.e. 50ppm
of oxygen. If you then change the output range to 500ppm, the alarm set point will remain half way up the new range,
and be displayed as 250ppm.
Change Alarm Set Points
Press one or the other ALARM SET POINT button for a second, and let go. While the alarm set point is showing, press
either the UP or DOWN arrow button and hold it until the value is what you want. The numbers will scroll slowly at
first and then speed up: if you press the other button, or release and re-press the one you are using, the number will
start going slowly again.
Alarm Hold Off
Press the ALARM HOLD OFF button for a second and release it. The display will show the alarm hold off time in
minutes, and if the analyzer was indicating an alarm, it will be turned off and held off for the period of the alarm hold
off time. The alarm hold off time can be adjusted by pressing the UP or DOWN arrow buttons.
Calibration (Spanning)
The model 201LC may be calibrated using air as the span gas, or else using a lower level gas closer to the measurement
range. It is not necessary to zero the analyzer. Spanning is normally performed somewhere between once a month
and once every three months, depending on the level of accuracy required.
Do not attempt to span with a gas less than 20% of the range to be used, as the span errors multiply and your results
will be less accurate. Make sure that the flow rate of span gas is the same as that of the process gas, unless you use air
as the span gas by opening the cell compartment.
If the span gas value is such that it will cause the alarms to activate, press the ALARM button to preemptively silence
them. You may want to extend the alarm hold of time to cover the length of time you will be spanning!
AIR CALIBRATION
1.
Shut down the sample gas flow, either by closing an external valve, or closing the internal flow valve.
2.
Open the cell cap, and blow a little compressed air under the cell. Don’t use your breath as it contains less
than 20.9% oxygen!
