A sampling point for use with an aspirating particle detection system. The sampling point includes: a body; a plurality of apertures in the body for drawing an air sample from an ambient environment; an outlet for delivering the sampled air, at a predetermined sample flow rate, from the body into a sampling pipe of the network of sampling pipes; and a means for maintaining the predetermined sample flow rate regardless of the presence or absence of ambient flow of air about the body. A particle detection system, and air sampling system are also described.