Jadak Photo Research SpectraScan PR-7 Series, User Manual

Page: 34 / 142

Chapter 3
– Theory of Operation
30
FIGURE 18
– PR-7XX SPECTROMETER
FIGURE 19 - PR-7XX SIMPLIFIED BLOCK DIAGRAM
The uncorrected or ‘raw’ spectrum is corrected using factors established during the factory calibration of the
instrument. These factors include wavelength accuracy correction, spectral distribution correction and photometric
correction. The wavelength calibration is performed using a helium spectral line source. The line source provides
known spectral emission lines that the software uses to map the dispersion of the grating to the multi-element
detector. The helium lines used during the wavelength calibration of the PR-730, PR-740, and PR-788 are 388.6
nm, 447.1 nm, 471.3 nm, 587.6 nm, 667.8 nm, 706.5 nm and 728.13 nm.
Spectrometer
CPU
Input Slit
Incident light
512 detector array
Diffracted light
Diffraction
grating
Objective
lens
Aperture Mirror
Optical
radiation
Eyepiece