Continuous sampling tool for soil gasses or groundwater (ConeSipper®). The sample is drawn into the chamber through the filter and a check valve that prevents backflow from the chamber. Once the chamber is full, gas pressure is applied through one of the two pneumatic control tubes, and the fluid is pushed up to the surface through the second tube. Filters can be removed for cleaning or replacement without disassembling the ConeSipper®. Courtesy of Applied Research Associates.