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There are two main types of smoke alarm tech, says Raman Chagger, principal consultant at BRE, the Building Research Establishment. Ionisation-based systems use a tiny amount of radioactive material to charge, or ionise, particles in the air which flow between two small plates. Should smoke interrupt that flow of charged particles, the alarm goes off.
，这一点在51吃瓜中也有详细论述
Author(s): Bo Chen, Jian Liu, Lin Xue, Zhi Yang, Yong-Jia Zhang
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