Patent ID: 7799567

Claim:
A method for collecting a sample of particulates entrained in a flow of fluid, comprising the steps of: (a) separating the fluid flow into a major flow and a minor flow, the major flow including a minor portion of particulates above a first predetermined size and the minor flow including a major portion of the particulates above the first predetermined size, the separation being performed using virtual impaction; (b) directing the minor flow onto a collection surface disposed within a housing of a sample device, such that particulates entrained in the minor flow are deposited on the collection surface, the deposition being performed using actual impaction; and (c) removing a portion of the particulates deposited on the collection surface to obtain a sample of the particulates, without removing the collection surface from the sample device in which the collection surface is disposed to collect the deposited particulates; and (d) regenerating the collection surface after the step of removing the portion of particulates to obtain the sample, such that particulates deposited on the collection surface prior to the step of regenerating the collection surface do not contaminate subsequent samples.