We often install hazardous gas detectors in our homes, and sometimes we hear false alarms. How can we determine if there's a genuine leak of hazardous gas in the home or if the detector is simply giving a false alarm?
Below, I'll share some possible causes of false alarms and how to avoid them. Please feel free to add anything I've missed in the comments section. Your participation is greatly appreciated.
➡️Characteristics of Combustible Gas Sensors and Potential False Alarms
Cross-sensitivity (Cross-interference): This is the most common cause. Many combustible gas sensors (especially catalytic combustion and metal oxide semiconductor types) don't only respond to the target gas. For example:
👉They are particularly sensitive to alcohol (ethanol) vapor and are prone to false alarms when using alcohol for disinfection, perfume, or alcohol-based cleaning agents in the kitchen.
👉They are sensitive to smoke, cooking fumes, and barbecue smoke; cooking fumes are very likely to trigger the alarm.
Responds to certain everyday volatile chemicals (such as paint, acetate-based cleaners, hairspray, and air fresheners).
👉Alcohols and Aldehydes: High concentrations of alcohol, acetone, acetaldehyde, etc., in the air can interfere with the sensor.
➡️Environmental and Usage Conditions That May Cause False Alarms
👉High Humidity and Condensation: Long-term dampness, condensation, or rapid humidity changes in the sensor can cause reading drift and false alarms.
👉Sudden Temperature Changes: Rapid heating or cooling can cause the sensor baseline to shift, resulting in momentary false alarms.
👉Dust and Oil Contamination: Oil and dust covering the sensor surface can alter sensitivity or generate false signals.
👉Oxidation/Aging: Prolonged sensor use, depletion of active materials, or poisoning (such as contamination by silicones or sulfides) can lead to changes in sensitivity and false alarms.
➡️How to Install Correctly and Avoid False Alarms
👉 When our product is first powered on, the sensor will enter a preheating phase (30 seconds). During this time, the readings are unstable and prone to false alarms. It is recommended to wait until the power is stable before entering monitoring mode. (Combustible gas sensors require preheating (generally tens of seconds to several minutes)).
👉 Near ventilation openings or exhaust fans: Airflow disturbances can affect detection.
👉 Improper installation location: Such as near stoves, open flames, or locations with a lot of steam.
➡️How to Reduce False Alarms
❌ Avoid exposing the alarm to sources of interference such as alcohol and cooking fumes as much as possible.
✔️ Clean and maintain regularly, as sensors have a limited lifespan. Replace the old device when it expires. Old devices may have been used for a long time.
✔️ Install in a well-ventilated location but avoid direct airflow from vents.