The invention relates to a method, a system and a computer program product for ascertaining a plant property of a useful plant in a field, wherein external data concerning the useful plant are stored in a memory unit, wherein a measurement device ascertains a raw measured value relating to at least one plant property, and wherein a calibrated or corrected value for the plant property is ascertained on the basis of the raw measured value taking account of the external data from the memory unit.

An apparatus including: a housing configured for installation in a landfill; a differential pressure sensor and at least one gas sensor in the housing; and a first valve configured to control landfill gas (LFG) flow to the at least one gas sensor, wherein the first valve is configured to open when the differential pressure sensor detects a selected pressure difference or pressure difference change between the atmospheric air pressure and the LFG pressure.

A control system for controlling extraction of landfill gas from a landfill via a gas extraction system comprising well piping, the landfill gas having a first temperature when extracted, the control system comprising: a gas composition chamber coupled to the well piping and comprising at least one sensor configured to measure one or more characteristics of a landfill gas sample in the gas composition chamber; a temperature control mechanism configured to heat the landfill gas sample in the gas composition chamber to a second temperature at least a threshold amount greater than the first temperature; and a controller configured to control the at least one sensor to measure the one or more characteristics of the landfill gas sample in the gas composition chamber when a temperature of the landfill gas sample in the gas composition chamber is at least the threshold amount greater than the first temperature.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for detecting seepage of hydrocarbons in subterranean zones. In one aspect, a method includes detecting hydrocarbon seepage at multiple different sampling depths from a surface in a surveyed geographic region, comparing each of the hydrocarbon seepage at the multiple different sampling depths, wherein hydrocarbon seepage at a reference depth is known, and determining hydrocarbon seepage through the surveyed geographic region based on a result of the comparison.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for detecting seepage of hydrocarbons in subterranean zones. In one aspect, a method includes detecting hydrocarbon seepage at multiple different sampling depths from a surface in a surveyed geographic region, comparing each of the hydrocarbon seepage at the multiple different sampling depths, wherein hydrocarbon seepage at a reference depth is known, and determining hydrocarbon seepage through the surveyed geographic region based on a result of the comparison.

Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for detecting seepage of hydrocarbons in subterranean zones. In one aspect, a method includes detecting hydrocarbon seepage at multiple different sampling depths from a surface in a surveyed geographic region, comparing each of the hydrocarbon seepage at the multiple different sampling depths, wherein hydrocarbon seepage at a reference depth is known, and determining hydrocarbon seepage through the surveyed geographic region based on a result of the comparison.

An apparatus for sampling landfill gas from a landfill flowing through a pipe. The apparatus may comprise: an enclosure configured to receive a section of the pipe; a gas sampling port in the section of the pipe; at least one sensor device disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the gas sampling port; and thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure. A method of operating a landfill gas recovery system. The method may comprise: flowing gas from a well riser pipe through a sampling subsystem to a collection system; and heating a portion of the sampling subsystem with the gas flowing from the well riser pipe to the collection system.

An apparatus for sampling landfill gas from a landfill flowing through a pipe. The apparatus may comprise: an enclosure configured to receive a section of the pipe; a gas sampling port in the section of the pipe; at least one sensor device disposed in a region of the enclosure, the at least one sensor being coupled to the section of the pipe through the gas sampling port; and thermal insulation positioned to retain heat from the section of the pipe in the region of the enclosure. A method of operating a landfill gas recovery system. The method may comprise: flowing gas from a well riser pipe through a sampling subsystem to a collection system; and heating a portion of the sampling subsystem with the gas flowing from the well riser pipe to the collection system.

A system for sampling sub-slab soil gas having an adaptor body that includes a first barbed portion, a collar portion, a second barbed portion, an internal cavity that axially passes through the length of the adaptor body, and a coupling portion. The system further includes one or more extensions such as a fitting extension, a filter extension, a sieve extension and a length extension, each of which are threadably retainable with the coupling portion of the adaptor body.

An insertion-type probe main body for insertion into a pipe transporting gas and a method for making such an insertion-type probe main body are provided. The probe main body includes: an elongate upper tubular portion; an elongate lower tubular portion which is integral with and having a diameter smaller than the upper tubular portion; a bore which extends between the upper and lower tubular portions; and helical fins integrally formed on the lower tubular portion and which wind along and around an outer surface of the lower tubular portion and which overlap each other. A radial extension of the lower tubular portion plus helical fins corresponds to an external radius of the upper tubular portion, so that the helical fins extend in a streamline fashion from the upper tubular portion. Numerous other aspects are provided.