User manual

1200 Series Variable Wavelength Detector User Manual 13
Introduction to the Variable Wavelength Detector 1
Lamp
The light source for the UV wavelength range is a deuterium lamp. As a result
of plasma discharge in a low pressure deuterium gas, the lamp emits light over
the 190 to 600 nm wavelength range.
Source Lens Assembly
The source lens receives the light from the deuterium lamp and focuses it onto
the entrance slit.
Entrance Slit Assembly
The entrance slit assembly has an exchangeable slit. The standard one has a
1-mm slit. For replacement and calibration purposes to optimize the
alignment, a slit with a hole is needed.
Filter Assembly
The filter assembly is electromechanically actuated. During wavelength
calibrations it moves into the light path.
The filter assembly has two filters installed and is processor-controlled.
A photo sensor determines the correct position.
OPEN nothing in light path
CUTOFF cut off filter in light path at λ >370nm
HOLMIUM holmium oxide filter for wavelength check.
Figure 3 Filter Assembly
Cutoff filter
Holmium oxide filter
with cutoff filter