Water and CO2 levels inside an FT-IR spectrometer vary according to changes
in the CO2 and water content of the laboratory air. Something as simple as the
number of people in the laboratory, or whether a window is open or closed, can
lead to changes in background spectral absorbances from one scan to the next.
The supply of CO2 free air to air bearing interferometer chambers eliminates
changes in spectral absorbances. Purging of the spectrometer body with CO2 free
air also retards the degradation of the beamsplitter through attack by moisture.
The result is increased accuracy of analyses and improved instrument reliability.
The Parker domnick hunter CO2 free air laboratory gas generator utilises formulated
molecular sieve beds to remove CO2 to levels below 1 ppm and water vapour to
a pressure dewpoint of - 70° C or better. Three-stage filtration removes
all suspended liquids, particles greater than 0.01 microns in diameter and non
methane hydrocarbons to > 0.003 ppm.
