MNL000423.doc
Revision 01
09/18/2018
© Versum Materials, Inc. as of the revision and date shown. All rights reserved.
Confidential and Proprietary Data
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5.2.7
Temperature Probe
The temperature feedback loop uses a Resistive Temperature Device (RTD) element to
accurately measure the temperature of the oil inside the thermowell in the container
and the corresponding temperature of the chemical.
The electronics were designed to compensate for the nonlinearity of the RTD element
to achieve higher accuracy. The probe has two other functions in addition to
temperature measurement which are over-temp interlock and proximity sensor
interlock.
The thermal cutout circuit will interlock the heater/cooler power in an over temperature
condition independent of processor control. Different models will have different cutoff
temperatures that are factory set.
The Trans-LC™ thermal cutoff is set to the temperature at which point the bubbler
could increase the pressure beyond the specifications of the quartz bubbler. The
proximity sensor will interlock the heater/cooler power when the probe is not installed at
the bottom of the thermowell or if the bubbler is not oriented in the Source Cup
properly.
Both over-temp and proximity sensors have been tested to reliability standards used in
UL certification (UL991) for use as safety interlocks.
