Abstract: A methane monitoring system including a filter, a flow restrictor and a methane level detector is disclosed. The sensor system draws gas from a piping system through a sample line into the filter. The filter removes moisture vapor from the gas, with the remaining gas passing into a flow meter. The flow meter regulates the gas pressure for the gas output to a sensing chamber containing the methane meter. The methane meter operates to sample the methane level in the gas and provides an electrical signal which can be output to a recording device such as a flash memory card or to real time remote reporting via direct connection or a wireless signal such as a cell phone, radio or satellite telecom system. Landfill gas which is introduced into the sensing chamber is then exhausted through vent slots in the housing.

Abstract: A chromatographic device comprises a tube, a chromatographic medium, a piston assembly, and a locking mechanism. The tube comprises first and second opposite ends and an inner surface. The inner surface of the tube at least in part defines an intermediate region. The intermediate region is generally between the first and second ends. The chromatographic medium is within the intermediate region. The piston assembly is within the tube and is positioned generally between the first end of the tube and the chromatographic medium. The piston assembly defines a passage for flow of process fluid. The piston assembly comprises a piston body portion. The locking mechanism is adjacent the piston assembly and is in engagement with the inner surface of the tube in a manner to prevent movement of the piston assembly relative to the tube axially toward the first end of the tube without preventing movement of the piston assembly relative to the tube axially toward the second end of the tube.