Patent ID: 7197949

Claim:
A method of sampling an environment for detecting the presence of an analyte, comprising the steps of: purging a diaphragm pump by drawing air through a filter at a first port on said diaphragm with an inlet valve open to draw air into a pump chamber and moving said filtered air through a second port into a separate buffer chamber, then into a sensor head, and out the first port inlet valve to said sensor head; closing said inlet valve and operating said diaphragm pump to move fluids therein into and out of said pump chamber through first and second ports to transfer filtered air to a buffer chamber for holding a quantity of filtered air from said pump chamber; intaking a sample of air potentially containing an analyte for contact by said air with said sensor head upon operation of said diaphragm pump with said inlet valve in its closed position, said sensor head operationally connected to said buffer chamber and adapted to identify the presence of a desired analyte and produce a signal in response to the quantity identified; and exhausting said sample of air from said sensor head out said first port on said diaphragm.