Analyzer shows oxygen sensor damaged or not detected Error 2
The “Error 2” message indicates that the oxygen sensor voltage is extremely low or not detected during startup. Follow the steps below to determine the cause.
Error 2 indicates that the analyzer is reading 0% oxygen and cannot detect a valid O₂ signal. Use the sections below to identify the cause and resolve the issue.
Possible causes-
Depleted or expired oxygen sensor
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Disconnected or damaged sensor cable
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Residual inert gas (e.g., argon, nitrogen, or helium) in the measuring path, displacing all oxygen
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Internal electronics malfunction
What to try
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Check the oxygen sensor date of manufacture. If the sensor is older than 24 months, replace it — sensors beyond this age are past their rated service life and will not measure reliably.
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Inspect the sensor cable for green oxidation, which indicates electrolyte leakage from the oxygen sensor. If oxidation is present, replace both the sensor and the cable (cable part number: 1035).
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If the last measured gas contained 0% oxygen (e.g., pure argon or nitrogen), flush the analyzer with ambient air for at least 60 seconds. If the reading does not recover, power the analyzer off, wait 10 seconds, then power it back on.
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If you have access to a known good oxygen sensor, install it and check whether Error 2 clears. If the error clears, the original sensor is faulty and should be replaced.
When to contact service
If Error 2 persists after replacing the sensor and cable, and after ruling out inert-gas contamination, the fault is likely internal. Return the analyzer to an authorized service center for diagnosis and repair.
Find your nearest authorized service center on the Divesoft Service Centers page.