Teledyne 501 TRS, Руководство по эксплуатации, Страница: 60 / 111

THEORY OF OPERATION Teledyne API - T102/501 TRS, Addendum to T101 Operation Manual
58
The Teledyne API UV Fluorescence SO
2
Analyzer is specifically designed to create
these circumstances.
•
The light path is very short (
x
).
• A reference detector measures the intensity of the available excitation UV
light and is used to remove effects of lamp drift(
I
0
).
•
The temperature of the sample gas is measured and controlled via
heaters attached to the sample chamber so that the rate of decay (k) is
constant.
• A special hydrocarbon scrubber removes the most common interfering
gases from the sample gas.
•
And finally, the design of the sample chamber reduces the effects of
stray light via its optical geometry and spectral filtering.
The net result is that any variation in UV fluorescence can be directly attributed to
changes in the concentration of SO
2
in the sample gas.
10.2.
The UV Light Path
The following information is in addition to that contained in the UV Light Path section
in the T101 Manual - PN 07266.
10.2.1.
UV Lamp Shutter & PMT Offset
Inherent in the operation of both the reference detector and the PMT are minor
electronic offsets. The degree of offset differs from detector to detector and from PMT
to PMT and can change over time as these components age.
To account for these offsets the T102 includes a shutter, located between the UV Lamp
and the source filter, that periodically cuts off the UV light from the sample chamber.
This happens every 30 minutes. The analyzer records the outputs of both the reference
detector and the PMT during this dark period and factors them into the SO
2
concentration calculation.
•
The reference detector offset is stored as and viewable via the front
panel as the test function DRK LMP.
• The PMT offset is stored as and viewable via the front panel as the test
function DRK PMT
07267B DCN6485