PerkinElmer Lambda 1050, Hardware Manual

Page: 62 / 82

62 . High-Performance Lambda Spectrometers Hardware Guide
Purging the Instrument
WARNING
Always purge the instrument with an inert gas such as nitrogen.
Never use a flammable gas such as hydrogen.
NOTE: You cannot purge the Lambda 650 or 750 spectrometers.
Oxygen absorbs radiation in the UV range below 190 nm, while water vapor absorbs
radiation in the NIR range between 1350 nm and 1450 nm, 1850 nm and 1950 nm, and also
between 2520 nm and 3000 nm. Best accuracy for measurements in these spectral regions
can be obtained only when the spectrometer is purged with nitrogen.
The entire optical compartment of the spectrometer is sealed. Radiation from the source
lamps enters the optical compartments through a window. The sample compartment is also
sealed from the optical compartment by windows. Thus the entire optical radiation path from
virtually the source lamp to the detector can be purged largely free of water vapor and
oxygen.
Fittings are provided on the left-hand side of the spectrometer for connection of a supply of
nitrogen, as shown in Figure 29. The inlet nearest the rear of the instrument is for the
sample compartment and the one nearest the front of the instrument is for the main optical
compartment. After purging these compartments, the nitrogen escapes to atmosphere.
Figure 29 Connectors for the purge gas supply
WARNING
Do not site the instrument in a poorly ventilated area if nitrogen will be
used as a purge gas.
Oxygen depletion in an enclosed space does not trigger a gasping reflex,
and errors of judgment, confusion, or unconsciousness can occur in
seconds and without warning.
Purge
inlets