3.2.3 Scaling Analog Outputs of the Analyzer
For certain applications, it may be desirable to change the analog output of the Series 9510 Carbon
Dioxide Analyzer over a narrower range of measurement. Users wi shing to do so can make this change
quite easily using the instrument’s front panel adjustment. As stated previously, the analyzer is equipped
with two analog outputs, 0-2 VDC and 4-20 mADC. It is shipped from the factory with the 0 PPM / % CO
2
equivalent to 0 VDC and 4 ma respectively, and the maximum scale value PPM / % CO
2
equivalent to 2
VDC and 20 mADC.
In order to adjust the zero points of the two analog outputs of the 9510, the instrument must be placed in
the scaling mode. To do so, press the “A2 & A3” buttons simultaneously and the front panel display will
respond by alternating the display [outL] or [outH] followed by the display of the existing CO
2
concentration
that is equivalent to 0 VDC. Adjust this value up or down by using the front panel up and down arrow
keys until the desired value is achieved. To adjust the span points of the two analog outputs of the Series
9510, press the UP and DN buttons simultaneously, and the instrument will toggle to the “span”
adjustment mode. The instrument will respond by alternating the display [outH] followed by the display of
the existing CO
2
concentration that is equivalent to 2 VDC and 20 mADC. Adjust this value up or down by
using the up and down arrow keys until the high value desired is displayed.
There are a few shortcuts for entering new values:
Pressing the [A1] key sets the value to 0;
Pressing the [A2] key sets the value to mid-scale for the range selected;
Pressing the [A1] and [A2] keys simultaneously sets the value to the maximum value for the range
of the analyzer.
Pressing the [A3] key will exit and display [CANCELLED]; the old values will not be changed.
The scaling software in the Series 9510 has built-in safeguards that will not allow the analyzer to be
adjusted so that the “outL” value is set above that of the current “outH” value, or have the “outH” value set
below that of the current “outL” value. To toggle from one mode to the other, depress the UP and DN
buttons simultaneously and make the required change. When the desired scaling values have been set,
press “A2 & A3” buttons simultaneously to leave the scaling mode. If you wish to exit the scaling mode
without any changes to the values currently entered, just press [A3]. If the analyzer is left in a “change
pending” state for over two minutes, the analyzer will automatically revert to the previous settings, and exit
the scaling mode.
NOTE: Regardless of how the analog outputs are scaled, the analyzer will always be capable of
displaying CO
2
concentrations up to the instrument’s maximum range.
Scaling the outputs does not
scale the front panel digital display.
Furthermore, CO
2
alarm relays, if not adjusted for the scaled range
of interest, will change state if the CO
2
values they are set at are met or exceeded.
ALPHA OMEGA INSTRUMENTS CORP.
SERIES 9510 CARBON DIOXIDE ANALYZER INSTRUCTION MANUAL
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