Thermo 42i - Page 136

Calibration
Calibration
4-8 Model 42i Low Source Instruction Manual Thermo Electron Corporation
The NO recorder response will equal:
Where:
URL = Nominal upper range limit of the NO channel, ppm
Record the [NO]
OUT
concentration and the NO response as indicated
by the recorder response.
7. Press to return to the Calibration menu, and choose Calibrate
NO
x
Coefficient.
8. Verify that the NO
x
calibration gas concentration is the same as the NO
calibration gas concentration plus any known NO
2
impurity.
The NO
x
line of the Calibrate NO
x
screen displays the current NO
x
concentration. The SPAN CONC line of the display is where you enter
the NO
x
calibration gas concentration.
Use and to move the cursor left and right and use
and to increment and decrement each digit. Press
to calibrate the NO
x
channel to the NO
x
calibration gas.
9. Press to return to the Run screen. The exact NO
x
concentration
is calculated from:
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
Z
+100 x
URL
]
[NO
=scale)(%ResponseRecorder
NO
OUT
F
+
F
+
F
)
]
NO
[+
]
[NO( x
F
=
]
NO
[
DONO
IMP
2
STD
NO
OUT
x