Experimental Study on Effects of Light Source and Different Smoke Characteristics on Signal Intensity of Photoelectric Smoke Detectors

Photoelectric smoke detectors, which detect smoke emitted in the early stages of fire, play a key role in automatic fire alarm equipment. When a fire is detected, the detector transmits an alarm signal to the control panel of the automatic fire alarm equipment. Therefore, the signal intensity and response speed of photoelectric smoke detectors are noteworthy research topics. This study designed an experiment system to explore the effect of different types of smoke on the signal intensity of commercial photoelectric smoke detectors. During a fire, different substances release smoke in different colors while burning. This variation may influence the response speed and sensitivity of smoke detectors. This study conducted an experiment using five types of powders to simulate the smoke release during a fire to test the response of photoelectric smoke detectors. This experimental method is more environmentally friendly as it did not involve any burning substance. The experiment results revealed that the photoelectric smoke detector generated different responses and signals of various intensities when detecting each type of smoke. This finding implies that fire alarm response time differs for different types of smoke. Experiment data revealed that when the detector light source was switched from IR LED to green LED, the sensitivity of the photoelectric smoke detector toward each type of smoke increased. The study findings provide a reference for improving the effectiveness and detection speed of photoelectric smoke detectors.