Teledyne 9110TH - Nitrogen Oxides Analyzer - Manual (Page 136)

Model 9110TH NOx Analyzer Operating Instructions
Teledyne Analytical Instruments 116
selects which physical range is in effect based on the analog output reporting range
selected by the user:
FOR THE 9110TM:
 Low range spans 0 to 20 ppm NO
X
(20 ppm = 5 V);
 High range spans 0-200 ppm NO
X
(200 ppm = 5 V).
If the high end of the selected reporting range is  20 ppm. The low physical
range is selected. If the high end of the selected reporting range is > 20 ppm.
The high physical range is selected.
FOR THE 9110TH:
 Low range spans 0 to 500 ppm NO
X
(500 ppm = 5 V);
 High range spans 0-5000 ppm NO
X
(5000 ppm = 5 V).
 If the high end of the selected reporting range is  500 ppm. The low
physical range is selected. If the high end of the selected reporting range is >
500 ppm. The high physical range is selected.
Once properly calibrated, the analyzer’s front panel will accurately report concentrations
along the entire span of its 0 and 200 ppm or 5,000 ppm physical range regardless of
which reporting range has been selected for the analog outputs and which physical range
is being used by the instruments software.
Both reporting ranges need to be calibrated independently to the same span gas
concentrations in order to allow switching back and forth between high and low ranges.