Patent ID: 7665345

Claim:
A gaseous product detecting device for detecting an airborne substance present in an air flow into the device, the device having at least one measuring cell and comprising at least one filtering element for retaining particulate present in air entering said at least one measuring cell while permitting the substance to pass through the at least one filtering element for detection, and at least one detecting element housed inside said at least one measuring cell to detect levels of the substance having passed through the at least one filtering element, wherein said device comprises a wall formed as part of said at least one measuring cell, said wall movable in a fluidtight manner between a withdrawn position, in which said at least one measuring cell has a maximum volume, and a forward position, in which said at least one measuring cell has a minimum volume, movement between the forward and withdrawn positions producing a pumping effect which draws the airborne substance through the at least one filtering element and into the at least one measuring cell for detection, and wherein the at least one detecting element is prevented from being impressed by resting against a shutter surface of said at least one measuring cell.