Thermo Scientific FTIR, User Manual

Page: 53 / 83

Operation
Using an eductor to generate vacuum
In place of the standard diaphragm pump, an Eductor panel may be used to generate the vacuum to
pull the sample gas through the sampling system. An Eductor uses compressed air to generate a
flowing stream, with the sample gas outlet connected via a tee fitting into the side of the flow. The
compressed air flow creates a vacuum force, pulling the sample gas through the eductor by means of
the Venturi effect.
The eductor panel uses the following fitting sizes:
l
For the 115 Volt model:
o
Instrument air inlet: 1/4 inch
o
Exhaust outlet: 3/8 inch
l
For the 230 Volt model:
o
Instrument air inlet: 6 mm
o
Exhaust outlet: 8 mm
See the plumbing diagram for the connecting the panel.
WARNING
Avoid toxic inhalation.
When sampling toxic gases, the exhaust must be connected to a safe vent
system.
Figure 4-6: Front of the eductor panel
48 Modular Gas System User Guide Thermo Scientific