Teledyne 9110T - Nitrogen Oxides Analyzer - Manual (Page 203)

Model 9110TH NOx Analyzer Calibration Procedures
Teledyne Analytical Instruments 203
9.3.2. SETUP FOR CALIBRATION WITH THE INTERNAL SPAN GAS
GENERATOR
Connect the sources of zero air and span gas as shown in Figure 9-4.
Figure 9-4: Pneumatic Connections for Manual Calibration/Checks with the Internal Span Gas
Generator
9.3.3. CAL ON NO
2
FEATURE
When using the IZS option to calibrate the 9110T, the analyzer’s CAL_ON_NO
2
feature must be turned
on. This feature enables a continuous zero gas flow across the IZS permeation tube and through the NO
2
converter. It also programs the analyzer to use the NO output from the NO
2
converter to calibrate the
span value of both NO and NO
X
.
Note This feature should only be enabled when a span calibration or calibration
check is performed.
While CAL_ON_NO
2
is enabled, the NO
2
concentration will always be reported as zero. This is
because the gas is continuously routed through the NO
2
converter and the analyzer’s firmware simulates
calibration with NO gas.
Table 9-1: IZS Option Valve States with CAL_ON_NO
2
Turned ON
Valve Condition Valve Port Connections
Sample/Cal Open to zero/span valve 1  2
Zero/Span Open to SPAN GAS inlet 1  2
NO/NO
x
Valve Open to NO
2
converter 1  2
Auto Zero Valve Cycles normally N/A
Since the instrument sees the same concentration of NO during both NO and NO
X
cycles, it reports an
NO
2
concentration of zero.
TO turn the CAL_ON_NO
2
feature ON/OFF, press: