The invention relates to an apparatus (100) for collecting dust samples. The apparatus comprises a piston (102) and a cylinder (110) for holding the piston with a body having a hole (108) extending through the body. The cylinder (110) has a first end (112), which is open, the first end of the cylinder being slanted such that underside (130) of the cylinder extends farther than upper side (132). A mechanism (114) moves the piston between inward and outward positions. The apparatus gathers dust flowing past the piston into the hole of the piston when the piston is in the outward position and moves the gathered dust by moving the piston into the inward position. An input feed (116) is configured to spread fluid through the hole filled with dust to flush the dust to an output feed (118).