Air sample chamber designs for improving electrostatic detection of particles by increasing the sensitivity of detecting radon gas in an air sample chamber. Examples includes convex shaped conductive elements disposed around a detector surface within an electrostatic participation detector chamber that form an effective electrostatic lens arrangement that increases an angle from which particles in the chamber are directed to the detector surface, which thereby increases the volume of the chamber above the detector surface from which charged particles can be captured.

A flow regulation device for volatile and semi-volatile sampling onto adsorbent media is provided. The flow regulation device includes a housing having an inlet, an outlet, a secondary inlet that is open to the ambient, a real time flow meter, a controller in electronic communication with the flow meter, and a three-way valve. Gas is drawn through the adsorbent media, into the inlet, and then to the outlet by a vacuum source joined to the outlet. The controller is configured to: (1) actuate the three-way valve to put the vacuum source in-line with the inlet; (2) continuously monitor the flow of gas through the inlet and calculate the time necessary to sample a pre-set volume of gas; and (3) after the pre-set volume of gas passes through the inlet, actuate the three-way valve to put the vacuum source in-line with the secondary inlet.

An aspirating detection system for monitoring for the presence of a pathogen, the aspirating detection system including: a network of one or more pipes for sampling air from a plurality of locations monitored by the aspirating detection system; a sensor unit 3 comprising a housing 13 fluidly connected to the network of one or more pipes, and a biosensor 12 mounted within the housing, the biosensor being configured to monitor for the presence of the pathogen; and an aspirator 15 configured to draw airflow through the network of one or more pipes and through the biosensor 12.