Ametek ASR900, Installation And Maintenance Manual

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1-2 | Heated Acid Gas Sample Probe (Large Diameter)
About the Heated Acid Gas Sample Probe
The Sample Probe is a heated probe that uses a dedicated temperature
controller to heat and maintain the temperature of the sample gas above
the sample dewpoint temperature. To do this, the analyzer uses a control
loop with a temperature sensor to control the temperature of the Sample
Probe.
The set points, Too Hot and Too Cold , depend on the application. The set
point is usually set at 10 °C above the sample dewpoint temperature, to
a maximum of 120 °C. The
Too Cold set point is typically a few degrees
below this and the Too Hot is typically a few degrees above.
The Probe Heater is protected from overheating by a temperature switch,
which will disconnect power if the Heater Assembly exceeds approximate-
ly 170 °C/338 °F. If the temperature of the probe falls below the analyzer
Too Cold parameter, the analyzer Microcontroller board will de-energize
the flow control valve to allow zero gas to backpurge the entire sample
system.
The aspirator draws sample gas from the process duct and through the
analyzer sample system, and then returns it to the process duct (see Fig-
ure 1-1 for an example plumbing schematic). Valves contained within the
probe allow for complete isolation of the sample system from the process
duct.
Figure 1-1 is an example drawing only. For your system, refer to
Final “As-Built” drawings in the Documentation Package shipped
with the analyzer/probe.
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NOTE