Ametek 932S

1-4 | Model 931S / Model 932S UV Analyzers
About the Analyzer Sample System
The sample gas is transported to and from the analyzer by the sample
stream pressure being higher than the vent pressure. For applications us-
ing the optional Heated Sample Probe, an aspirator (within the probe) is
used to return the used sample gas to the process.
The major components of the sample system and their functions are
detailed below. The components listed below are for a variety of analyzer
configuration possibilities. Depending on your application, only some of
these components will be used. The sample system consists of (see Figures
1-2 and 1-3):
Component Function
Sample Probe Extends into the sample stream to obtain a representative
sample. Can be heated or unheated. Heated probes return
used gas sample to the sample stream.
Sample Shut-O󰀨 Valve Isolates the sample path from the sample stream.
Heated Sample/Vent Lines
Optional – Used to keep the sample gas above the dewpoint
temperature (application-specic). Some applications vent the
used gas sample to a low pressure are header (<0.5 PSIG).
Measuring Cell The Measuring Cell is a chamber of known length, with
optical-grade quartz windows, through which the radiation
beam passes through the gas sample. The windows are sealed
by means of o-rings and removable end caps.
The Measuring Cell can be unheated (typical) or heated
(optional) to keep the sample gas above the dewpoint. Other
variations of Measuring Cells are also available.
Pressure Regulator The pressure regulator is used to set the proper sample
pressure in the sample system if the process pressure is higher
than the analyzer operating pressure (refer to Final “As-Built”
drawings in the analyzer Documentation Package).
Filter AMETEK recommends installing a coalescing or membrane
lter upstream of the Measuring Cell.
Zero Solenoid The zero solenoid allows Zero gas (or Span gas) to ush the
sample system during the Auto-Zero (or Span) process.
Flow Indicator The ow meter provides a visual indication of the sample ow
rate in liters/minute through the analyzer. Please note that the
scaling on the ow indicator is for air at standard temperature
and pressure. Its purpose is to indicate and ensure that
appropriate ow conditions are maintained and not to provide an
absolute measure of the ow of sample gas. When the oat is in
the centre, the sample ow is approximately 2.5 L/min (5 SCFH).
Some systems use a rotameter instead of the Flow Indicator.
Filterblock Assembly (optional)
The Filterblock Assembly removes condensables and
particulates from the sample gas.
Heated Sample Probe Optional – Used to maintain the temperature of the Sample
Probe Assembly above the sample dewpoint temperature.
Includes an aspirator which provides suction to move the
sample gas through the sample path. Refer to the Heated Acid
Gas Sample Probe Installation and Maintenance Guide for
complete details.