The Go Direct® O2 Gas Sensor (GDX-O2) contains an electrochemical cell that has an average lifespan of about six years when stored properly (upright).

When new, the Go Direct O2 Gas Sensor has a relative stability reading of approximately 99-97 at ambient levels of O2 gas (20.9%). This relative stability reading is found in the calibration dialog.

This electrochemical cell degrades over time, but the sensor will still give good readings provided it is calibrated. However, once the relative stability reading for ambient air has dropped below 55, the sensor can produce unstable readings and is considered dead.

If you suspect your sensor is dead, contact Vernier for technical support. We will verify the issue and can offer a free refurbishment if the sensor is still under warranty (less than 5 years old).

If your sensor is out of warranty, we can replace the electrochemical cell for a fee. This refurbished sensor will have a 1-year warranty from the time it was returned you.

Contact Vernier Technical Support for further questions.

This information is regarding the Go Direct® O2 Gas Sensor (GDX-O2). For similar information on the O2 Gas Sensor (O2-BTA) please see