Teledyne MD300 - Oxygen analyzer and monitor (Diving) - Manual (Page 28)

Operation AD300/MD300
Teledyne Analytical Instruments 28
Freeze the sensor or instrument.
Open or try to repair a leaking or broken sensor.
Immerse the unit or sensor in any liquid.
Pass hot or cold gas mixtures over the sensor.
Adjust the reading in air after 100% calibration
Use cleaning agents or liquids in the cable receptacles or around
the battery compartment.
Store the unit in hot or humid environment.
Expose the LCD to excessive sunlight.