Teledyne 6200A Manual page 57

TAI Model 6200A SO
Ultraviolet light is focused through a narrow 214 nm bandpass filter into the reaction chamber. Here
it excites the SO molecules, which give off their characteristic decay radiation. A second filter
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allows only the decay radiation to fall on the PMT. The PMT transfers the light energy into the
electrical signal which is directly proportional to the light energy in the sample stream being
analyzed. The preamp board converts this signal into a voltage which is further conditioned by the
signal processing electronics.
The UV light source is measured by a UV detector. Software calculates the ratio of the PMT output
and the UV detector in order to compensate for variations in the UV light energy. Stray light is the
background light produced with zero ppb SO
will convert this electrical signal into the SO
number of SO molecules.
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Analyzer Operator Manual, 02164, Rev. G
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. Once this background light is subtracted, the CPU
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concentration which is directly proportional to the
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