A particle detecting device is provided. The particle detecting device includes a base, a detecting element, a micro pump and a drive control board. The base includes a detecting channel, a beam channel and a light trapping region. The detecting element includes a microprocessor, a particle sensor and a laser transmitter. The particle sensor is disposed at an orthogonal position where the detecting channel intersects the beam channel. When the micro pump, the particle sensor and the laser transmitter are enabled under the control of the microprocessor, the gas outside the detecting channel is inhaled into the detecting channel. When the gas flows to the orthogonal position where the detecting channel intersects the beam channel, the gas is irradiated by the projecting light source from the laser transmitter, and projecting light spots generated are projected on the particle sensor for detecting the size and the concentration of suspended particles.

A particle detecting device is provided. The particle detecting device includes a base, a detecting element, a micro pump and a drive control board. The base includes a detecting channel, a beam channel and a light trapping region. The detecting element includes a microprocessor, a particle sensor and a laser transmitter. The particle sensor is disposed at an orthogonal position where the detecting channel intersects the beam channel. When the micro pump, the particle sensor and the laser transmitter are enabled under the control of the microprocessor, the gas outside the detecting channel is inhaled into the detecting channel. When the gas flows to the orthogonal position where the detecting channel intersects the beam channel, the gas is irradiated by the projecting light source from the laser transmitter, and projecting light spots generated are projected on the particle sensor for detecting the size and the concentration of suspended particles.

A particulate detecting element includes a casing having a gas flow channel that enables gas to pass therethrough, a charge generating unit configured to impart charges generated by electric discharge to the particulates in the gas introduced into the casing and turn the particulates into charged particulates, a collection electrode disposed in the casing, where the collection electrode collects a collection target representing one of the charged particulate and the charge not imparted to the particulate, and a deceleration electrode disposed such that at least part of the deceleration electrode is away from an outer wall of the gas flow channel in the casing, where the deceleration electrode generates a deceleration electric field that decelerates the collection target at least one of upstream of the collection electrode in a gas flow direction and above the collection electrode.