248 1100 Series FD Reference Manual
7 Introduction to the Fluorescence Detector
The flow cell is a solid quartz body with a maximum back pressure of 20 bar.
Excessive back pressure will result in destruction of the cell. Operating the
detector close to waste with low back pressure is recommended. A slit is
integrated to the quartz body.
The luminescence from the sample in the flow cell is collected at right angles
to the incident light by a second lens, and passes through a second slit. Before
the luminescence reaches the emission monochromator, a cut-off filter
removes light below a certain wavelength, to reduce noise from 1
st
order
scatter and 2
nd
order stray light, see Figure 80 on page 247.
The selected wavelength of light is reflected onto the slit in the wall of the
photo-multiplier compartment of the optical unit. The bandwidth of the
emitted light is 20 nm.
Figure 81 Cross-Section of Flow Cell