Calibration
Calibration
Thermo Fisher Scientific
Model 42
i
Trace Level Instruction Manual
4-13
Use
to move the cursor left and right and use
to increment and decrement the numeric character at the cursor.
3.
Press
to calculate and save the new NO
x
coefficient based on the
entered span concentration.
4.
Press
to return to the Run screen. The exact NO
x
concentration
is calculated from:
F
+
F
+
F
)
]
NO
[
+
]
[NO
(
x
F
=
]
NO
[
D
O
NO
IMP
2
STD
NO
OUT
x
Where:
[NO
x
]
OUT
= diluted NO
x
concentration at the output manifold, ppm
[NO
2
]
IMP
= concentration of NO
2
impurity in the standard NO cylinder, ppm
The NO
x
recorder response will equal:
Z
+
100
x
URL
]
NO
[
=
scale)
(%
esponse
Recorder R
NO
OUT
x
x
Where:
URL = Nominal upper range limit of the NO
x
channel, ppm
5.
Record the NO
x
concentration and the analyzer's NO
x
response.
Use the following procedures to prepare the NO, NO
x
, and NO
2
calibration curves.
1.
Generate several additional NO and NO
x
concentrations by decreasing
F
NO
or increasing F
D
.
2.
For each concentration generated, calculate the exact NO and NO
x
concentrations using the above equations for [NO]
OUT
and [NO
x
]
OUT
.
3.
Record the NO and NO
x
responses.
4.
Plot the analyzer responses versus the respective calculated NO and
NO
x
concentrations and draw or calculate the respective calibration
curves. For subsequent calibrations where linearity can be assumed,
these curves may be checked with a three-point calibration consisting of
Preparing NO, NO
x
, and
NO
2
Calibration Curves
