Teledyne T100 Instruction Manual page 223

Teledyne ML - T100 UV Fluorescence SO2 Analyzer

The amount of exited SO
9-2) above: concentration of SO
and;

The amount of fluorescent light created which is affected by the variable factors from
(Equation 9-5): the amount of SO
on the temperature of the gas.
second stage of this reaction occurs after the SO
Because the The system will seek the lowest available stable energy state, the SO
molecule quickly returns to its ground state (Equation 10-3) by giving off the excess
energy in the form of a photon (h). The wavelength of this fluoresced light is also in
the ultraviolet band but at a longer (lower energy) wavelength centered at 330nm.
SO *    
2
The amount of detectable UV given off by the decay of the SO
which this reaction occurs (k).
F 
Where:
F
=
the amount of fluorescent light given off.
k
=
The rate at which the SO
*
SO =
Amount of excited SO
2
Therefore:
 
k SO *   
2
Finally, the function (k) is affected by the temperature of the gas. The warmer the gas,
the faster the individual molecules decay back into their ground state and the more
photons of UV light are given off per unit of time.
In summary, given that the absorption rate of SO
fluorescence (F) is a result of:
* created which is affected by the variable factors from (Equation
2
When and the intensity of the light (I
the temperature of the gas is known and compensated for so that the rate of SO
is constant (k). and; no interfering conditions are present (such as interfering gases or
stray light); the amount of fluorescent light emitted (F) is directly related to the
concentration of the SO
2
06807A(DCNxxxx)
SO  hv
2
 
k SO *
2
* decays into SO
2
in the sample chamber.
2
F
 SO  hv
2
; intensity of UV light (I
2
* present and the rate of decay (k) which changes based
2
) is known; path length of excited light is short (x);
0
in the Sample Chamber.
Theory Of Operation
reaches its excited state (SO
2
330 nm
(Equation 9-3)
* is affected the rate at
2
(Equation 9-4)
2.
330 nm
(Equation 9-5)
(a) is constant, the amount of
2
); path length of the UV light(x)
0
*).
2
*
2
*decay
2
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