Jenway 6320D - Manual (Page 15)

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3.2 SPECTROSCOPY MEASUREMENT
There are four main components of a spectrophotometer. These are a light source to emit a high
and constant amount of energy over the full wavelength range; a method for separating the light
into discreet wavelengths; a sample holder and a light detector.
The optical layout of the 6300 and 6320D spectrophotometers is shown below:
Figure 3.2.1 – Diagram of light path
The light from the pre-focused tungsten halogen lamp is focused onto the grating, with 1200 lines
per millimeter, which separates the light into discreet wavelengths. The diffracted spectrum of
light then passes through a further slit and lens arrangement before passing through the sample
in the sample chamber from left to right. The light which is not absorbed by the sample is
transmitted through a collecting lens and onto the signal detector. The photo-diode detector used
is mounted directly onto the detector PCB and is used to calculate the % transmittance. The result
is displayed either as % transmittance or absorbance on the instrument display.