Variable flow path width virtual impactor and particle detecting device
A virtual impactor includes a jet nozzle that jets, from a jet outlet, a gas that contains particles, an opposing nozzle that is disposed with a specific separation distance from the jet nozzle and draws in, as a secondary flow, from a vacuum inlet at one end portion, a portion of the gas that is jetted from the jet nozzle, and a variable mechanism that varies at least one of a width of the jet outlet, the specific distance, and a width of the vacuum inlet.
1. A virtual impactor comprising:
a first flow path in which a fluid that includes particles flows;
a second flow path that has a intersecting portion that intersects the first flow path, and branches a portion of the fluid; and
a flow path width adjusting unit that changes a width of a flow path at the intersecting portion between the first flow path and the second flow path, to set a cross-sectional area of the fluid to a desired value, wherein
the flow path width adjusting unit comprises:
four flow path structuring members disposed in a form of a matrix;
a top plate and a bottom plate, holding both faces of the four flow path structuring members therebetween; and
a distance adjusting unit that sets a separation distance between flow path structuring members.