Figure 10-1: Uv Absorption - Teledyne 100E Instruction Manual

Theory Of Operation
The second stage of this reaction occurs after the SO
Because the system will seek the lowest available stable energy state, the SO
quickly returns to its ground state (Equation 10-3) by giving off the excess energy in the
form of a photon (hν). The wavelength of this fluoresced light is also in the ultraviolet
band but at a longer (lower energy) wavelength centered at 330nm.
Obviously the more SO
detected in the sample chamber. Unfortunately there are several other factors that also
can affect the amount of fluorescence detected by the analyzer.
For instance, the amount of SO
and not its peak intensity because some of the photons are absorbed by the SO
light travels through the sample gas.
The equation for defining the average intensity of the UV light (Ia) is:
Where:
I
•
0
a
•
SO
•
x
•
164
SO *   →
2
that is present in the sample gas the more fluorescence will be
2
* is dependent on the average intensity of the UV light
2

Figure 10-1: UV Absorption

[
=
Ia I 1
0
=
Intensity of the excitation UV light.
=
The absorption coefficient of SO
=
Concentration of SO
2
=
The distance between the UV source and the SO
being affected (path length).
Model 100E Instruction Manual
reaches its excited state (SO
2
kF
 SO + hv
2 330
( (
− −
exp ax SO
2
in the sample chamber.
2
nm
(Equation 10-2)
]
) )
2
(Equation 10-3)
.
molecule(s)
2
045150102 Rev XB1
*).
2
* molecule
2
as the
2