Oh wow I just looked up solenoid valves and that is such a better idea! That's why I came here, being as this is my first project developing hardware I'm a little naive as to what components are out there. Thank you so much!
The pressures are very low, normal air pressure. Basically the particulate counter just pulls air past a laser to measure the diffraction caused by particles in the air and calculates the level of particulate off from that.