Principle Of Operation; Optical System - Hitachi U-2910 Instruction Manual

2.3 Principle of Operation

2.3 PRINCIPLE OF OPERATION

2.3.1 Optical System

Concave diffraction grating
Exit slit
Filter (F)
Mirror (M4)
Half mirror
(HM)
Mirror (M3)
Fig. 2-5 Optical System of Model U-2910 Spectrophotometer
Fig. 2-5 shows the optical system of Model U-2910. The white
light emitted from the light source is led to the monochromator of
Seya-Namioka mount that utilizes a concave diffraction grating
(with grating constant of 1/600 mm, blaze wavelength of 250 nm,
and diffraction area of 20 mm  25 mm), where it is transformed
into a monochromatic beam. The beam from the monochromator
then passes through a filter, toroidal mirror (M2), and is separated
into sample beam and reference beam by half mirror (HM).
The sample beam that has passed through the sample in the
sample compartment enters a detector, where it is converted into
electric signal. The reference beam also passes through the
sample and enters a detector in the same way, and this signal is
used as a reference in photometry.
Entrance slit
Reference
side
Mirror (M2)
Monochromator
D lamp
2
WI lamp
Sample
side
Sample compartment
2 - 4
Mirror (M1)
Lens
Detector 2
Lens
Detector 1