E8500 Instruction & Operations Manual
version 1.017
Page 16 of 49
NO
2
and SO
2
are gases that are highly soluble in water. To prevent significant loss of
NO
2
and SO
2
during transport of the sample from the probe to the analyzer, the
following conditions must be satisfied:
1. Rapid sample transport. This is accomplished by maintaining a high flow rate
using a relatively small diameter sampling line.
2. Preferably use of a sample line made from a highly hydrophobic material, such
as Teflon, Viton, or stainless steel.
3. Minimum contact of the gas sample with the water collection mechanism and
also no additional condensation to occur following the thermoelectric chiller. This
is accomplished by using a specially designed Peltier cooled manifold to
separate the gas from the water.
Additionally, an optional SCU (Sample Conditioning Unit) shown in the photo below can
be used to dry the stack gas before it passes through the sample hose. The SCU is
recommended for applications of high moisture applications and/or when measuring
Low NOx or Low SO
2
.
SCU (Sample Conditioning Unit)
Condensate Catch Pot (included
with the SCU) with manual drain
plug
