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Equipment Required
Thermo Fisher Scientific
Chapter 4
Calibration
This chapter describes procedures for performing a multipoint calibration
of the Model 42i Trace Level. The information described here is considered
be adequate to perform the calibration. However, if greater detail is desired,
the user is referred to the Code of Federal Regulations, Title 40, Part 50,
Appendix F.
The calibration technique is based on the rapid gas phase reaction between
NO and O
which produces stoichiometric quantities of NO
3
accordance with the reaction:
NO
+
The quantitative nature of this reaction is such that when the NO
concentration is known, the concentration of NO
Ozone is added to excess NO in a dynamic calibration system, and the NO
channel of the chemiluminescence NO- NO
indicator of changes in NO concentration.
When O
is added, the decrease in NO concentration observed on the
3
calibrated NO channel is equivalent to the concentration of NO
produced. Adding variable amounts of O
change the amount of NO
required apparatus and procedures for calibrating the instrument:
"Equipment
Required" on page
●
"Pre-Calibration" on page
●
"Calibration" on page
●
"Calibration in Dual Range and Auto Range
●
"Zero and Span
Check" on page
●
The following equipment is required to calibrate the analyzer:
ν
→
O
+
+
h
NO
O
3
2
2
-NO
2
from a stable O
3
generated. The following sections discuss the
2
4-1
4-8
4-9
4-20
Model 42i Trace Level Instruction Manual
in
2
can be determined.
2
analyzer is used as an
x
2
generator can
3
Mode" on page
4-16
4-1
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Troubleshooting
