43Iqtl Principle Of Operation - Thermo Scientific 43iQTL Instruction Manual

43iQTL Principle
of Operation
Thermo Scientific
The 43iQTL operates on the principle that SO
ultraviolet (UV) light and become excited at one wavelength, then decay to
a lower energy state emitting UV light at a different wavelength.
Specifically,
SO
+
2
The sample is drawn into the 43iQTL through the SAMPLE bulkhead, as
shown in Figure 1–2. The sample flows through a hydrocarbon "kicker,"
which removes hydrocarbons from the sample by forcing the hydrocarbon
molecules to permeate through the tube wall. The SO
through the hydrocarbon "kicker" unaffected. The sample then flows into
the fluorescence chamber. Pulsating UV light is focused by a condensing
lens into the mirror assembly. The mirror assembly contains eight selective
mirrors that reflect only the wavelengths which excite SO
pulsating UV light excites the SO
A photodetector, located at the back of the fluorescence chamber,
continuously monitors the pulsating UV light source and is connected to a
circuit that compensates for fluctuations in the UV light.
As the excited SO molecules decay to lower energy states they emit UV
2
light that is proportional to the SO
allows only the wavelengths emitted by the excited SO
the photomultiplier tube (PMT). The PMT detects the UV light emission
from the decaying SO
As the sample leaves the optical chamber, it passes through a flow sensor, a
capillary, and the "shell" side of the hydrocarbon kicker. The sample then
flows to the pump and is exhausted out the EXHAUST bulkhead of the
analyzer. The 43iQTL outputs the SO
display and the analog outputs, and also makes the data available over the
serial or Ethernet connection.
h υ SO * SO
→ →
1 2 2
molecules in the fluorescence chamber.
2
concentration. The bandpass filter
2
molecules.
2
concentration to the front panel
2

43iQTL Principle of Operation

molecules absorb
2
h υ
+
2
molecules pass
2
molecules. The
2
molecules to reach
2
43iQTL Instruction Manual
Introduction
1-3