Patent ID: 7487794

Claim:
A device for determining the presence of undesirable effects of a gaseous medium, the device comprising a housing having a cylindrical cavity and a compartment capable of holding a cylindrical cavity and a compartment capable of holding an indicator medium, the device also comprising a cylindrical flow control body which is slidably moveable within the housing cavity between a first position and a second position, the flow control body comprising a first seal and a second seal fixed eternally to the flow control body, which seals form between them a void around the flow control body and in fluid contact with in inlet and an outlet of the housing, the void having first and second void parts, the flow control body also comprising a third seal fixed externally to the flow control body between the first and second seals, forming between the first seal and the third seal the first void part and forming between the third seal and the second seal the second void part, the flow control body having an inner elongated cavity with one end in fluid contact with the first void part and the other end in contact with the indicator medium when present in the device, wherein the flow control body in the first position forms a first passageway between the second and third seals for the gaseous medium comprising the inlet, the second void part and the outlet, and in the second position forms a second passageway between the first and third seals for the gaseous medium comprising the inlet, the first void part, the elongated cavity of the flow control body, the second void part and the outlet.