Provided herein is an apparatus for determining a vertical density profile of a multi-layered fluid column including at least two different liquids, the apparatus comprising a plurality of measurement modules that form a vertical array of measurement modules; wherein each measurement module comprises: a support arm mounted to the elongate vertical support member and extending outwardly from the elongate vertical support member; a displacer carried on the support arm; and a force measurement device configured to measure a force attributable to a mass of the displacer mediated by a buoyancy of the displacer in the fluid column, wherein the plurality of measurement modules have a data connection to a data processing unit that is configured to process the measurement data from the plurality of measurement modules and generate a level or density profile of the fluid column.

Provided herein is an apparatus for determining a vertical density profile of a multi-layered fluid column including at least two different liquids, the apparatus comprising a plurality of measurement modules that form a vertical array of measurement modules; wherein each measurement module comprises: a support arm mounted to the elongate vertical support member and extending outwardly from the elongate vertical support member; a displacer carried on the support arm; and a force measurement device configured to measure a force attributable to a mass of the displacer mediated by a buoyancy of the displacer in the fluid column, wherein the plurality of measurement modules have a data connection to a data processing unit that is configured to process the measurement data from the plurality of measurement modules and generate a level or density profile of the fluid column.

Invention is a device to allow a person to self-measure hydrostatic weight.

The method comprises of using the device (Buoyometer) in a pool or other body of liquid of known density to counter the force of gravity pulling the body downwards. The point of neutral buoyancy—that is the point where the Buoyometer's buoyancy exactly equals the gravitational force is measured and from that hydrostatic weight is calculated.

Hydrostatic weight is then used to assess body density—and thus body composition—using previously determined empirical equations.

A specific gravity measurement apparatus has a specific gravity hydrometer that carries a codestrip at the top. A linear optical encoder is disposed to view the codestrip and to output electronic signals that are indicative of a movement of the codestrip relative to said encoder. The movement is indicative of a change in the specific gravity of the liquid, such as a change in a salinity of the aquarium water in which the hydrometer floats. The measurement apparatus may be incorporated into a saltwater aquarium salinity control system where an electronic controller uses the measurement inputs to control a plurality of pumps for selectively adding saltwater or freshwater to the aquarium water in order to control the salinity of the water at a given setpoint level.

A specific gravity measurement apparatus has a specific gravity hydrometer that carries a codestrip at the top. A linear optical encoder is disposed to view the codestrip and to output electronic signals that are indicative of a movement of the codestrip relative to said encoder. The movement is indicative of a change in the specific gravity of the liquid, such as a change in a salinity of the aquarium water in which the hydrometer floats. The measurement apparatus may be incorporated into a saltwater aquarium salinity control system where an electronic controller uses the measurement inputs to control a plurality of pumps for selectively adding saltwater or freshwater to the aquarium water in order to control the salinity of the water at a given setpoint level.

Systems and methods for determining fluid density include receiving calibration data for a fluid density measurement tool. The fluid density measurement tool can include a cantilever beam and at least one strain sensor that is coupled to the cantilever beam. The cantilever beam can be housed in the fluid density measurement tool and is buoyed by a fluid that enters the fluid density measurement tool. The systems and methods measure strain values at the at least one strain sensor and determine a density of the fluid based on the calibration data, and the strain values measured at the at least one strain sensor.

A method for determining the amount of a gas present in a battery cell, whereby the battery cell has an initial volume, comprises at least the following steps: a) immersing the battery cell into a non-conductive liquid having a defined density at a first ambient pressure; b) generating a lifting force that acts in the opposite direction of a downforce of the battery cell; c) changing the first ambient pressure to a second ambient pressure, and measuring the buoyancy force—which is dependent on the ambient pressure—of the battery cell in the liquid; and d) measuring the amount of gas present in the battery cell, taking into account the first and second ambient pressures, the buoyancy forces ascertained for these ambient pressures, the temperature of the non-conductive liquid and the density of the liquid.

A method for determining the amount of a gas present in a battery cell, whereby the battery cell has an initial volume, comprises at least the following steps: a) immersing the battery cell into a non-conductive liquid having a defined density at a first ambient pressure; b) generating a lifting force that acts in the opposite direction of a downforce of the battery cell; c) changing the first ambient pressure to a second ambient pressure, and measuring the buoyancy force—which is dependent on the ambient pressure—of the battery cell in the liquid; and d) measuring the amount of gas present in the battery cell, taking into account the first and second ambient pressures, the buoyancy forces ascertained for these ambient pressures, the temperature of the non-conductive liquid and the density of the liquid.

A device is disclosed, including: a plate including a sample deposition tube adapted to receive a sample comprising one or more analytes, the sample deposition tube defining a vertical axis substantially perpendicular to a main surface of the plate; and a mirror positioned to project, substantially parallel to the main surface of the plate, an image of the sample deposition tube along its vertical axis, so as to allow determination of the vertical location of the one or more analytes inside the sample deposition tube. Methods for determining the density of one or more analytes using various embodiments of the device are also described.

A device is disclosed, including: a plate including a sample deposition tube adapted to receive a sample comprising one or more analytes, the sample deposition tube defining a vertical axis substantially perpendicular to a main surface of the plate; and a mirror positioned to project, substantially parallel to the main surface of the plate, an image of the sample deposition tube along its vertical axis, so as to allow determination of the vertical location of the one or more analytes inside the sample deposition tube. Methods for determining the density of one or more analytes using various embodiments of the device are also described.