Abstract: A portable device for detecting an analyte associated with a target organic molecule in a liquid and/or solid substance. The device includes a test chamber, a probe, and a sensor. The test chamber contains a liquid volume of test solution including an analytical reagent selected to react with the analyte. The test chamber is sealed by a pierceable membrane wall. The probe is removably positionable to pierce the membrane wall to deposit a sample in the test chamber to form a test mixture with the test solution. The sensor is positioned to detect one or more characteristics of the test mixture in the test chamber indicative of a reaction between the analyte and the analytical reagent.

Abstract: A portable device for detecting an analyte associated with a target organic molecule in a liquid and/or solid substance. The device includes a test chamber, a probe, and a sensor. The test chamber contains a liquid volume of test solution including an analytical reagent selected to react with the analyte. The test chamber is sealed by a pierceable membrane wall. The probe is removably positionable to pierce the membrane wall to deposit a sample in the test chamber to form a test mixture with the test solution. The sensor is positioned to detect one or more characteristics of the test mixture in the test chamber indicative of a reaction between the analyte and the analytical reagent.

Abstract: A portable device for detecting an analyte associated with a target organic molecule in a liquid and/or solid substance. The device includes a test chamber, a probe, and a sensor. The test chamber contains a liquid volume of test solution including an analytical reagent selected to react with the analyte. The test chamber is sealed by a pierceable membrane wall. The probe is removably positionable to pierce the membrane wall to deposit a sample in the test chamber to form a test mixture with the test solution. The sensor is positioned to detect one or more characteristics of the test mixture in the test chamber indicative of a reaction between the analyte and the analytical reagent.

Abstract: A portable device for detecting an analyte associated with a target organic molecule in a liquid and/or solid substance. The device includes a test chamber, a probe, and a sensor. The test chamber contains a liquid volume of test solution including an analytical reagent selected to react with the analyte. The test chamber is sealed by a pierceable membrane wall. The probe is removably positionable to pierce the membrane wall to deposit a sample in the test chamber to form a test mixture with the test solution. The sensor is positioned to detect one or more characteristics of the test mixture in the test chamber indicative of a reaction between the analyte and the analytical reagent.

Abstract: This invention concerns improvements to gravity gradient instruments (GGI) and in particular to the accelerometers that are paired within these instruments. Accelerometers have a proof mass suspended by a spring within a magnetic field. An internal feedback loop provides a signal related to movement of the proof mass back through a reaction coil retaining the proof mass in the magnetic field, to maintain the proof mass stationary. An external feedback loop adjusts the accelerometer scale factor. The internal feedback loop provides second order compensation to the proof mass and the spring stiffness. In a further aspect the invention is a method of matching accelerometer pairs.

Abstract: This invention concerns improvements to gravity gradient instruments (GGI) and in particular to the accelerometers that are paired within these instruments. Accelerometers have a proof mass suspended by a spring within a magnetic field. An internal feedback loop provides a signal related to movement of the proof mass back through a reaction coil retaining the proof mass in the magnetic field, to maintain the proof mass stationary. An external feedback loop adjusts the accelerometer scale factor. The internal feedback loop provides second order compensation to the proof mass and the spring stiffness. In a further aspect the invention is a method of matching accelerometer pairs.

Abstract: This invention concerns improvements in the performance of a mobile gravity gradient instrument (GGI). Gravity gradiometers measure one or more components of the gradient of gravity which is expressed as the gradient of a gravity vector, or in other words a tensor. The instrument comprises a first, second, third and fourth accelerometer equally spaced around the circumference of a circle, with their sensitive axes tangential to the circle, and arranged in opposing pairs with the first accelerometer opposite the second, and the third accelerometer opposite the fourth. In use the accelerometers are spun around an axis normal to the circle which passes through its center. A summing amplifier receives the outputs of the accelerometers and combines them in a manner to cancel the common mode output signals and so produces all instrument output. One or more feedback loops extend from the instrument output to one or more of the accelerometers to compensate for errors.