Abstract: Disclosed is a plasma generator. The plasma generator may include a gripping portion including at least one interface unit configured to receive an input from a user; a head portion including a plasma generating portion configured to generate the plasma; a first cartridge configured to detachably couple at a first end of the head portion and generate the plasma over a predetermined region; and a light irradiation portion provided at a second end of the head portion.

Abstract: A light-scattering dust sensor includes: a light scattering region; a light emitter configured to emit light to the light scattering region; a light receiver configured to receive scattered light generated in the light scattering region; and an emitted light limiter located between the light emitter and the light scattering region, wherein the light emitted by the light emitter includes: peripheral light; and central light having an intensity that is more uniform than an intensity of the peripheral light, wherein the emitted light limiter is configured to block part of the emitted light, wherein the part of the emitted light blocked by the emitted light limiter includes the peripheral light.