Teledyne 9110AH - Nitrogen oxides analyzer - Manual (Page 98)

TELEDYNE Model 9110AH NO
X
Analyzer Operator Manual, 01620, Rev. F
7-10
Table 7-8: Calibration Requirements for AutoRange or Remote Range
No matter which calibration method you choose from this chapter, all of the following
parameters must be set to properly calibrate the instrument on AutoRange or Remote range.
Parameter Low Range High Range
Range Low Range is selected by pressing
CONC-LO on the front panel. High Range is selected by pressing
CONC-HI on the front panel
Slope NO
x
and NO slopes for low range
are set by span calibration
NO
x
and NO slopes for high range
are set by span calibration
Offset NO
x
and NO offsets for low range
are set by zero calibration
NO
x
and NO offsets for high range
are set by zero calibration
Converter Efficiency CE can be set by one of the
procedures in Section 7.10.
Converter efficiency is optional. CE can be set by one of the
procedures in Section 7.10.
Converter efficiency is optional.
7.8 Calibration Requirements for Independent Range
In Independent Range mode there is one set of calibration parameters. That is, NO
x
and NO
slopes and NO
x
and NO offsets, and one converter efficiency parameter. The calibration of the
M9110AH using independent range is the same as calibration in single range. To achieve
independent ranges, the computer scales the 3 outputs using the ranges keyed in by the
operator.
7.9 Calibration Quality
After calibration is complete, it is very important to check the QUALITY of the calibration. The
calibration of the M9110AH involves balancing several sections of electronics and software to
achieve optimum accuracy, noise, linearity and dynamic range.
The slope and offset parameters are similar to the span and zero pots on an analog instrument.
Just as in the analog instrument, if the slope or offset get outside of a certain range, the
instrument will not perform as well.
The slope value will be slightly different on the NO and NO
x
channels. This is due to slight
differences in pneumatic resistance in each pathway. If the slopes are significantly different,
there is a calibration error or a cross port leak in the switching valve. If there is a sudden
change in slopes after a calibration, that usually indicates a change in reaction cell pressure.
Check the Troubleshooting Section 9.