Thermo Scientific Accela UV/Vis Plus, Hardware Manual

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1
Introduction
Functional Description
2 Accela UV/Vis Detector Hardware Manual Thermo Scientific
Functional Description
The Accela UV/Vis Detector is a full-featured, time-programmable, variable-wavelength
UV/Vis (ultraviolet/visible) absorbance detector. It operates in either the single or dual
wavelength mode in the UV or visible ranges.
The UV/Vis detector is a benchtop unit for inclusion into the Accela LC System. You control
the detector remotely over an Ethernet communications link from a Thermo Scientific data
system computer.
The UV/Vis detector consists of a dual light source, an optical bench (see Figure 2 ), dual
photodiode detectors, and several printed circuit boards (PCBs).
Figure 2. Accela UV/Vis Detector optical bench
To provide a complete spectrum of ultraviolet and visible light, the detector uses a
deuterium lamp (D2) for the UV range (190 to 365 nm) and a tungsten lamp (W) for the
visible range (366 to 800 nm). The lamp cover has a safety interlock that reduces the
possibility of human exposure to harmful UV light. When you remove the cover, the lamps
automatically turn off. A computer-controlled shutter selects which lamp to use for sample
analysis. The light from the selected lamp goes to a holographic grating that disperses the light
into a spectrum. The grating turns to select the programmed wavelength. For precise
wavelength control, a stepper motor controls the alignment of the grating. A system of baffles
that reduces stray light in the optical bench increases the absorbance linearity.
Tungsten
lamp
Deuterium
lamp
Sample
photodiode
Reference
photodiode
Lens
Flow cell
Beamsplitter
Shutter
Grating