14
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 7300 and 7305 spectrophotometers is shown below:
Figure 3.2.1
– Diagram of light path
The light from the pre-focused tungsten halogen (7300) or pre-aligned xenon (7305) 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.
Summary of Contents for 7300
Page 1: ...Operating Manual 730 005 REV D 08 14 Model 7300 and 7305 Spectrophotometer...
Page 2: ...2...
Page 56: ...56 SECTION 11 Declaration of Conformity...
Page 57: ...57...
