|Analog output reading is unchanging and appears incorrect.
|Analog output is in error state.
|Remove the cause of the error state and the analog output will recover its normal function.
|Probe outputs stars "****" on serial line instead of measurement data.
|Incorrect supply voltage.
|Check the power supply.
Check the active errors using the ERRS command on the serial line.
|Unsuitable operating environment.
|Verify that the operating environment is within specified operating limits.
|Unable to access probe on the RS-485 line.
|Check that the RS-485 connection is wired correctly.
|Probe in POLL mode with unknown address.
|Power cycle or reset the probe and try again.
|CO2 measurement not working.
|Condensation on the sensor.
|Remove the filter and check if condensation has formed on the sensor. If yes, dry out the condensation with instrument air and insert a new dry filter. Keep the probe powered and operating to prevent re-occurrence.