Spectrophotometer

1
Spectrophotometer

• Measures intensity as a function of the
  wavelength of light
• Common application A-logT

2
Spectrophotometer
UV-Vis-NIR spectra used to detemine concentration
or absorptivity IR spectra used to identificate
compounds.
3
Spectrophotometer
Quantitative analysis use wavelength at which
transmittance is maximum
4
Spectrophotometer

• 2 measurement classes
• single beam - absolute light intensity
• double beam - ratio of the light intensity on 2
  different light paths more stable measurement.

5
UV-VIS-NIR Cary 500 spectrophotometer

• Two lamps deuterium lamp for UV
• Tungsten lamp for VIS/NIR
• Two detectors R928 Photomultiplier for UV/VIS
  (range 175-850nm)
• Cooled PbS detector
  for NIR (range 800-3300nm)
• Wavelength range 175 3300nm
• Wavelength accuracy UV/VIS ?0.1nm, NIR ? 0.4nm
• UV/VIS limiting resolution lt0.05nm
• Spectral bandwidth UV/VIS 0.01 to 5nm in 0.01nm
  steps
• NIR 0.04 to
  20nm
• Maximum scan rate UV/VIS 2000nm/min, NIR
  8000nm/min