Abstract: Methods and devices for measuring chemical or biological properties of a liquid from a subsurface position are disclosed, wherein a closed casing is submerged in the liquid to be sampled. The flow of the liquid for the sampling is driven by a hydrostatic pressure and is thus independent of pumps or the like when placed at the correct subsurface position. The flow rate is in a first aspect of the present invention controlled by providing a constant hydrostatic pressure during the sampling period. Alternatively, the inlet is provided with a cartridge comprising a tracer material, which is partly soluble by the liquid and is released proportional to the flow rate.

Abstract: Methods and devices for measuring chemical or biological properties of a liquid from a subsurface position are disclosed, wherein a closed casing is submerged in the liquid to be sampled. The flow of the liquid for the sampling is driven by a hydrostatic pressure and is thus independent of pumps or the like when placed at the correct subsurface position. The flow rate is in a first aspect of the present invention controlled by providing a constant hydrostatic pressure during the sampling period. Alternatively, the inlet is provided with a cartridge comprising a tracer material, which is partly soluble by the liquid and is released proportional to the flow rate.

Abstract: A device and a method for measuring fluid flow and solute mass transport in flow systems includes a casing (1) having inlet (3) and outlet (9) openings and a fluid passageway therebetween, the casing containing at least one fluid permeable insoluble adsorbent matrix (7) and at least one tracer material (5, 5?) located in the fluid passageway. The tracer material (5,5?) is a fluid permeable partially soluble material which at least prior to installation is not physically or chemically bonded to the adsorbent matrix (7) and is either mixed with the adsorbent matrix or is located in at least one section (4,4?) of the casing (1) separate from but in contact with at least one section (6,6?) of the casing holding the insoluble adsorbent matrix (7,7?). The device is intended to be installed in a medium having a fluid path therein.

Abstract: A device and a method for measuring fluid flow and solute mass transport in flow systems includes a casing (1) having inlet (3) and outlet (9) openings and a fluid passageway therebetween, the casing containing at least one fluid permeable insoluble adsorbent matrix (7) and at least one tracer material (5, 5?) located in the fluid passageway. The tracer material (5,5?) is a fluid permeable partially soluble material which at least prior to installation is not physically or chemically bonded to the adsorbent matrix (7) and is either mixed with the adsorbent matrix or is located in at least one section (4,4?) of the casing (1) separate from but in contact with at least one section (6,6?) of the casing holding the insoluble adsorbent matrix (7,7?). The device is intended to be installed in a medium having a fluid path therein.