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.
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Thanks to Steven Forsythe for sharing a report on the use of agar seaweed in Britain during WWII, Barbara Buchberger at the Robert Koch Institute for pointing out Koch’s use of gelatine for the identification of cholera, and the surviving relative of Fanny Angelina Hesse for sharing a trove of unpublished material.
Филолог заявил о массовой отмене обращения на «вы» с большой буквы09:36