Troubleshooting the alarm when NO₂ readings are out of expected range
A "NO₂ readings out of expected range" alarm fires when at least 25% of the raw NO₂ readings in the last three-hour period are outside the expected range of -500 to 500 ppb. This article explains what causes it and when to act.
It may clear on its own
Fast changes in temperature or humidity can shift the NO₂ electrochemical cell sensor's baseline, and those swings can trigger this alarm temporarily.
Monitor the device for 3 days to see whether the alarm clears and the sensor returns to a stable baseline.
If the alarm persists
If it doesn't clear, this can indicate an electrochemical cell failure and electrolyte leak, and the device will most likely need to be replaced. Contact support@clarity.io to start that process.
What's next
- Why are my NO₂ measurements missing a calibration?
- When to recalibrate or replace your Node-S.
- See all device alarms.
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Still need a hand? Email us at support@clarity.io or create a support ticket, and our team will get back to you.