0024-9551
Revision 1
61
PCA
®
400 User Manual
Message
Message Type
Description
T-STK Disconnected
Warning
The probe thermocouple is not connected to
the analyzer’s T-Stack connector. Plug the probe
thermocouple plug into the T-Stack connector at the
bottom of the instrument.
Bad Sensor
Error
O
2
sensor output is too low and cannot be calibrated in
the instrument and needs replaced.
Low Sensor
Warning
O
2
, CO
LOW
, CO
HIGH
, NO, NO
2
or SO
2
sensor output(s) were
low but still usable. Sensor(s) may need to be replaced
in the near future. Message will indicate which sensor(s)
are in warning.
Off Bias - O2
Warning
The O
2
sensor has been without power for a prolonged
period and has lost bias. The sensor will be disabled
until it has stabilized.
Off Bias - NO
Warning
The NO sensor has been without power for a prolonged
period and has lost bias. The sensor will be disabled
until it has stabilized.
Applied Value High or
Low
N/A
An attempt was made to calibrate a sensor outside its
calibration range.
Warm-up Sensor Error
Error
• CO, CO
HIGH
, NO, NO
2
, or SO
2
sensor(s) were not
zeroed at warm-up because of high output. Run
instrument in fresh air then restart instrument to
re-zero sensor(s). If message persists, sensor(s) may
need to be replaced. Message will indicate which
channel(s) are in error.
• Stack or Air temperature channel is measuring
temperature outside the range of -4 to 212° F
(-20 to 100° C)
at startup. Make sure that the Stack
and Air Thermocouples are sampling ambient
room air within the temperature range at startup.
• Pressure sensor is measuring pressure outside
the range of ±3 inches of water column at startup.
Ensure that the analyzer is sampling atmospheric
pressure and restart the analyzer.
• The instrument was turned on with the probe
sampling flue gas. Move the probe to fresh air and
restart the analyzer.
6. Remove Calibration Cylinder
Turn OFF regulator and remove the 500 ppm CO cylinder.
5.7 Troubleshooting
5.7.1 Error Codes