Teledyne 6020 - Photometric analyzer - Manual (Page 64)

1-2 Part II
1 Operational Theory Model 6020
Teledyne Analytical Instruments
1.2 Optical Bench
Depending on the application, the analyzer comes with one of
the following types of lamps: Deuterium (D), Quartz Iodine (L), or Mercury
(Hg). Energy from the lamp, used as a source, is focused through a sample cell
onto a photo detector. In front of the detector is a motor-driven filter disc
containing two optical filters mounted 180 degrees apart that alternately and
continuously rotate into and out of the light beam. Sample flows continuously
through the sample cell and absorbs optical energy at various wavelengths
depending on its composition.
The analyzer monitors two wavelengths: a measuring wave-
length selected where the component of interest has a characteristic absorption
peak and a reference wavelength that provides stability by compensating for
extraneous phenomena such as turbidity, cell window deposits, unequal optical
component aging, etc.
Figure 6 Shown without an Integral General Purpose Control Unit