43Iq Principle Of Operation - Thermo Scientific 43iQ Instruction Manual

43iQ Principle of
Operation
Thermo Scientific
The 43iQ operates on the principle that SO
(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 43iQ 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, where pulsating UV
light excites the SO molecules. The condensing lens focuses the pulsating
2
UV light into the mirror assembly. The mirror assembly contains four
selective mirrors that reflect only the wavelengths which excite SO
molecules.
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
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 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 43iQ 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
concentration. The bandpass filter
2
molecules. The photodetector, located at the back
2
concentration to the front panel
2

43iQ Principle of Operation

molecules absorb ultraviolet
2
h υ
+
2
molecules pass
2
molecules to reach
2
43iQ Instruction Manual
Introduction
2
1-3