The electronic filter, as its name implies, uses electronic and optical techniques combined with special algorithms to realize the filter function and eliminate the non-smoke (dust, water vapor and PM10, PM2.5 soot) interference in the fire alarm. This technology has been patented. After testing, the warning threshold is set to 0.05% obs/m, the sensitivity is 0.001% obs/m, and the non-smog effect is eliminated as follows:

1. When the filter aperture is set at 1.0, it can eliminate dust above PM10 (particle size above 10uM), for example, dust that is generally lifted by the floor sweeper or vacuum cleaner.

2. When the filter aperture is set to 1.0-0.7, the influence of water vapor, such as kettle steam and water vapor generated by the humidifier, can be eliminated.

3. When the filter aperture is set to 0.7-0.5, the smoke effect caused by the burning of the plastic bag can be eliminated.

4. When the filter aperture is set to 0.5, the effect of PM2.5 (particle size below 2.5um) can be eliminated, and the smoke generated by the plastic bag is eliminated.

5. When the filter aperture is set to 0.4-0.3, the effect of soot can be eliminated. At this time, cigarette smoke can still be detected, so it is more reliable than the fire alarm for cigarette smoke detection.

By analyzing the test data, in the case where the warning threshold is set to 0.05% obs/m, the general technical solution is within 24 hours, and the PM2.5 is in the case of severe pollution of 400 ug-500 ug/cubic (usually the explosion table). The number of reports is 106 times, basically in the alarm state. The VESDA technical solution is falsely reported 24 times. The false positive report duration is short, generally within 10 minutes, and our technical solution has no false positives, but the concentration is detected as 0.043% obs. /m, close to the alarm value, lasts 15 seconds, and the smoke is 0 at other times.

In the case of severe contamination, PM2.5 can achieve a value of 0.800% obs/m when photodetecting smoke, and a value of 0.200% obs/m in a good range. Due to the high volatility of PM2.5, according to meteorological test data, within 1-2 hours, it can be from serious pollution to mild pollution. Whether it is rising or falling, PM2.5 is fluctuating. Sex, through the electronic filter technology, you can truly achieve no false alarms under ultra-high sensitivity. As the sensitivity decreases, the possibility of false positives does not exist. For example, the sensitivity is 0.02%obs/m-0.05%obs/m, which is basically no false alarm. It can fully meet the needs of very early fire alarms in high-polluting environments in China and can eliminate Dust and moisture effects.