A second chamber known as a reference chamber in detectors is used to prevent false alarms caused by what?

The reference chamber in fire detectors is primarily designed to account for changes in atmospheric pressure and humidity. This chamber allows the detector to differentiate between the actual presence of airborne particulates, which might indicate smoke from a fire, and other environmental factors, such as humidity or barometric pressure changes that could trigger a false alarm.

The reference chamber effectively acts as a baseline, measuring the normal environmental conditions and identifying deviations caused by fire-related phenomena. When combined with the main sensing chamber, this setup helps to improve the reliability of the detection system, ensuring it only triggers alarms under conditions indicative of an actual fire.

This design is especially important in settings where humidity levels fluctuate frequently, as high humidity can impact the sensitivity of smoke detectors. Therefore, the reference chamber's role is crucial in preventing unwanted alarms that do not signify a fire emergency.