Waters 2489, Operator'S Manual

Page: 21 / 234

Principles of operation 1-5
Waters 2489 UV/Visible Detector optics assembly
Optics assembly light path
The detector provides an extremely efficient design for exceptionally high
light throughput. It operates as follows:
1. The ellipsoidal mirror collects light from the lamp and focuses it through
the filter wheel onto the entrance slit. The spherical mirror directs light
toward the grating. A different portion of the spherical mirror focuses
dispersed light of a particular wavelength band, determined by the
grating angle, onto the entrance of the flow cell. Light exiting the flow
cell passes through the cuvette location to the sample photodiode.
2. The beamsplitter, located just ahead of the flow cell, diverts a portion of
the light to a reference photodiode.
3. When you enter a new wavelength through the detector’s front panel (or
through Empower™ or MassLynx™ software), the detector rotates the
grating to the appropriate position.
TaperSlit
Flow Cell
D
2
lamp
Slit
Spherical
mirror
Grating
Optional
Beamsplitter
Window
cuvette
Filter
wheel
Ellipsoidal
mirror
Sample
photodiode
Reference
photodiode