Abstract: An embodiment a pressure compensated pH sensor apparatus, including: a pH sensing component comprising a sensing portion that is exposed to a fluid source when in use; a pressure chamber located in a position under the sensing portion and that surrounds all of the sensing portion not exposed to the fluid source when in use; and a pressure compensation mechanism located within the pressure chamber, wherein the pressure compensation mechanism reacts to pressure from an environment outside the apparatus, thereby support the sensing portion.

Abstract: Systems and methods for buoyancy compensation are provided. Both active and passive buoyancy compensation can be provided using a compressible mixture made of a liquid along with a hydrophopic material such as a powder, electrospun fiber, or foam. The compressible fluid compresses as pressure is applied or expands as pressure is released thereby substantially maintaining an overall neutral buoyancy for a vessel. This allows the vessel to ascend and descend to water depths with minimal active buoyancy change. As a result, the energy usage and the reliance on higher pressure air and oils can be minimized.

Abstract: Technology is provided for an aqueous solution constituent analyzer. The analyzer includes an ultraviolet light emitting diode (LED) with a current source providing variable current thereto. A spectrometer is positioned for receiving light from the LED transmitted through an aqueous solution. A controller receives radiant flux data for a plurality of wavelengths and determines, based on the radiant flux data, a usable number of the plurality of wavelengths that satisfies a relative uncertainty threshold. The controller can increase the current to the LED if the usable number of wavelengths is less than a minimum threshold and calculate a concentration of a constituent of interest in the solution. The controller can also determine a peak wavelength of the plurality of wavelengths having the greatest intensity value, and decrease the current level to the LED if the peak wavelength has an intensity value greater than a saturation value for the spectrometer.

Abstract: Systems and methods for buoyancy compensation are provided. Both active and passive buoyancy compensation can be provided using a compressible mixture made of a liquid along with a hydrophopic material such as a powder, electrospun fiber, or foam. The compressible fluid compresses as pressure is applied or expands as pressure is released thereby substantially maintaining an overall neutral buoyancy for a vessel. This allows the vessel to ascend and descend to water depths with minimal active buoyancy change. As a result, the energy usage and the reliance on higher pressure air and oils can be minimized.

Abstract: Systems and methods for buoyancy compensation are provided. Both active and passive buoyancy compensation can be provided using a compressible mixture made of a liquid along with a hydrophopic material such as a powder, electrospun fiber, or foam. The compressible fluid compresses as pressure is applied or expands as pressure is released thereby substantially maintaining an overall neutral buoyancy for a vessel. This allows the vessel to ascend and descend to water depths with minimal active buoyancy change. As a result, the energy usage and the reliance on higher pressure air and oils can be minimized.