Micro-GASS
The Micro-GASS systems prepare gas samples
for analysis by electro-chemical sensor (ECS) analyzers when the sample
is hot and wet. These sensors are a very reliable means of detecting the
presence of toxic or explosive compounds in a gas stream but in
moisture-saturated samples, sensor life is greatly reduced due to
condensation within the cell and subsequent leakage of electrolyte. ECS
can also be used with corrosive samples like stack gases, but also
suffer reliability problems when the sample humidity is too wet. The
Micro-GASS system reduces sample humidity to the ideal range for ECS,
typically 30 to 70% R.H., while also removing any dust or dirt particles
present.
Micro-GASS units offers full corrosion
resistance and very high selectivity, so complex samples can be
processed without loss of analyte gases. Nafion dryer technology is the
driving force behind this system. Operating as a self-contained unit,
the Micro-GASS incorporates a built-in sample pump to draw the sample
gas through a 0.1µ filter then into a MD-Series™ Nafion gas dryer where
water vapor is absorbed into and through the membrane walls. The dried
sample then flows to the sensor where the measurement is made. After
exhausting from the ECS, the gas passes through a needle valve and
expands, causing a reduction in vapor pressure. It then re-enters the
dryer to be used as a purge gas. Because the purge gas is generated from
the exhaust stream of the sensor, it makes the Micro-GASS a
self-regenerating and transportable conditioning system, relying only on
a power source.
Typical applications for the Micro-GASS
sample conditioning system include monitoring of boiler and burner
efficiencies. |