Ametek 241CE II

PN 903-8797, Rev A
Warming Stage
The Warming Stage begins immediately after the Cooling Stage ends. The
new HCDP temperature – obtained during the Cooling Stage – is displayed on
the User Interface. During this stage, the power applied to the Thermoelectric
Cooler is reduced stepwise to zero to allow the mirror temperature to increase
at a controlled rate of approximately 10 °C/minute (18 °F/minute). The heat
sources for warming the mirror are the Measuring Cell, the contained sample
gas, and the Heatsink.
If the determined value exceeds its associated alarm setpoint, or the Status
Code (SCode) indicates malfunction of the analyzer (by means of a Fault or
Warning alarm), the appropriate system relay is activated and its correspond-
ing LED on the User Interface is turned On. If the alarm is a Fault alarm, the
alphanumeric display on the User Interface will also ash. The SCode is deter-
mined by the built-in diagnostics function.
The Warming Stage continues until either:
• The mirror temperature reaches a temperature (a user-specied value,
typically 10 °C/18 °F) above the HCDP temperature detected during the
previous Cooling Stage,
or
• The mirror temperature is 5 °C (9 °F) below its High setpoint,
or
• If, after 2 minutes the mirror temperature has not increased.
At this point the Warming Stage ends and a new measuring cycle begins, start-
ing with the Purging/Hold Stage.
However, if the Warming Stage terminates because the mirror temperature has
not increased after 2 minutes, the Stage-Time-Out (“w TimeOut”) SCode and
Warning-Stage-Time-Out (“w Warm TimeOut”) XSCode are generated.
2-34 | 241CE II Hydrocarbon Dewpoint Analyzer