E8500 Instruction & Operations Manual
version 1.017
Page 23 of 49
sensors and also monitors the temperature of the cells as required by the
EPA’s Method CTM-034.
B. Stack temperature sensor
The thermocouple is located at the tip of the probe. It measures the stack
temperature minus the ambient temperature. The thermocouple junction is a
shielded, ungrounded, inconel sheathed, type K thermocouple with a capability
of measuring temperatures from 0 to 2000 ºF. The instrument software
linearizes the thermocouple output to improve the accuracy.
C. Draft sensor / Gas velocity sensor.
If the analyzer comes with the stack gas velocity option (separate S-type pitot
tube and tubing), the pressure sensor, located inside the analyzer, is a very low
range (0-10” WC) pressure sensor.
If the analyzer does not have the gas velocity option, then the pressure sensor
is a 0-1 PSI, higher range sensor for the measurement of stack draft.
Pressure / velocity will zero every time an autozero countdown is carried out.
