PARTICLE DETECTION SENSOR, DUST SENSOR, SMOKE DETECTOR, AIR CLEANER AND VENTILATOR

PROBLEM TO BE SOLVED: To provide a particle detection sensor capable of preventing particles from adhering inside.SOLUTION: A particle detection sensor 1 includes: a light projection element 10 and a light receiving element 20 for detecting particles contained in the atmosphere by receiving scattered light from a light projection element 10 due to particles in a detection area DA with a light receiving element 20. A first protection plate 61 which has the light transmissivity is disposed at a connection part between a particle flow path 33 which is a space area including a detection area DA where the atmosphere containing particles flows and a light-receiving area 32 as space area for guiding the scattered light to the light receiving element 20. 【課題】内部に粒子が付着することを抑制できる粒子検出センサを提供する。【解決手段】投光素子１０と受光素子２０とを備え、検知領域ＤＡにおける粒子による投光素子１０の光の散乱光を受光素子２０で受光することにより大気中に含まれる粒子を検出する粒子検出センサ１であって、検知領域ＤＡを含む空間領域であって粒子を含む大気が流れる空間領域である粒子流路３３と前記散乱光を受光素子２０に導くための空間領域である受光領域３２との接続部分に、透光性を有する第１保護板６１が配置されている。【選択図】図１