Ametek Thermox 2000 ATEX Series User Manual page 135

Zero Gas Range Error
This error message occurs if the calibration zero gas does not read within
the software's allowable limits. Once this error occurs, calibration of the
system is aborted. This error indicates one of the following problems:
Calibration gas setup problem
Process pressure incorrectly entered.
Cell wiring reversed (Cell + and Cell - wires)
Aspirator air not turned off during calibration (WDG-IV only)
Failed cell (primary calibration should be run at this time)
Leak or plug in plumbing
Maintenance and Troubleshooting | 6-7