Drawell DU-8800DS Series, User Manual

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3
Fig1
Working Principle:
The spectrophotometer consists of five parts: 1) Halogen or deuterium lamps
to supply the light; 2) A Monochromator to isolate the wavelength of interest
and eliminate the unwanted second order radiation; 3) A sample compartment
to accommodate the sample solution; 4) Two detectors to receive the
transmitted light and convert it to an electrical signal; and 5) A digital display to
indicate absorbance or transmittance. The block diagram (Fig 2) below
illustrates the relationship between these parts.
Block diagram for the Spectrophotometer
Fig 2
In your spectrophotometer, light from the lamp is focused on the entrance slit
of the monochromator where the collimating mirror directs the beam onto the
grating. The grating disperses the light beam to produce the spectrum, a
portion of which is focused on the exit slit of the monochromator by a
collimating mirror. From here the beam is passed to a sample compartment
through one of the filters, which helps to eliminate unwanted second order
radiation from the diffraction grating. Upon leaving the sample compartment,
the beam is passed to the silicon photodiode detector and causes the detector
to produce an electrical signal that is displayed on the digital display.
Power switch Fuse
Fan
Power socket USB Port Parallel Port