Crowcon Tetra MO7237, User Manual, Page: 33 / 36

XII. Troubleshooting guide
Symptom/ Cause Action
error message
Instrument won't switch on Flat battery. Recharge or replace battery.
Pump not running The pump is a PC Reconfigure with PC
configurable option. software.
No confidence beep Function disabled. Reconfigure with PC software.
Gas reading when no gas Zero drifted. Restart instrument in clean
present air.
Unstable/inaccurate gas Sensor failure Do not use; exit hazardous
reading area immediately. Return
instrument for recalibration
or sensor replacement.
Autozero failed Zeroing in Switch off and restart in
contaminated clean air.
atmosphere
Cannot autozero due to Zeroing in Switch off and restart in
alarm contaminated clean air
atmosphere
Calibration expired The calibration due Send for calibration
date has passed
Flow fail clear blockage Sample tube is Clear blockage and press
blocked with water button to restart pump
or dirt or kinked
LCD too faint/dark Contrast setting Adjust using Portables
wrong PC software.
Tetra Troubleshooting guide
Fatal/Auto shut
Service
Configuration
User alert
Calibration