MAPADA M4 UV-VIS Technical Manual page 13

monochromatic light selected by grating scattering passes through 3# Reflector Mirror,
the filter, exit slit, and splits into 2 beams by the beam splitter. One beam passes through
1# Lens, the sample cell, 2# Lens and arrives at the detector to form the measuring path,
which is used to measure the samples. The other beam passes through 3# Lens and arrives
at the detector to form the monitoring path, which is used to monitor light source change
and improve stability.
Figure 4-1 Optical system
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