Innovation in PSI Instruments:

GTD-Pro:
The PSI GTD-Pro measures the sum of the pressures of dissolved gases in water. It is innovative in featuring a gas permeable membrane that is supported by a rigid porous support. The porous support is critical for function at hydrostatic pressures greater than a few meters. The GTD-Pro planar support is effective in resisting pressures to 150 meters depth, and instruments fitted with the PSI tubular support (patent pending) have been certified to be proof against pressures to 1000 meters depth.

CO2-Pro:
The CO2-Pro incorporates several important Company innovations. One of these is a tubular rigidly supported gas transfer interface (patent pending). This interface provides much more rapid equilibration than is offered by a flat interface, and has been tested and shown to resist hydrostatic pressures as great as 1470 psi. A further innovation is in placing this tubular interface inside a channel through which water is pumped. This approach substantially improves the equilibration time of the instrument by decreasing the thickness of the mass transfer boundary layer. The tubular interface and its configuration inside the pumped channel are the subjects of patent applications. Other innovations lie in anti-fouling methods (patent pending) and data logging/ instrument control.

 

Methods for measuring and monitoring ocean processes have changed dramatically over the past few decades. Only a few years ago, chemical measurements were made on water samples collected from shipboard. While this method is still being used, ship based measurements provide information only about the conditions at the time of the ship's visit and do not typically provide the time series necessary to understand ocean variability. Consequently, researchers have developed alternative deployment methods including moorings, gliders, profilers and other autonomous instrumented vehicles. These alternative platforms require accurate, stable and low powered instruments that are capable of long-term deployment. Satisfying these measurement needs is among the principle objectives of R&D at PSI.

Very early we recognized that a sensor that measures pressure could offer exceptional precision and long-term accuracy for measuring dissolved gases. At PSI we subsequently developed an in situ instrument (the GTD-Pro) for measuring gas tension that is highly accurate, precise, and stable. Our GTD-Pro has now been used by numerous researchers to provide the measurements for understanding a broad range of aquatic processes. Our GTD-Pro has an accuracy of better than 0.02 % per year, and a precision of microbars.

PSI continues to invest in research and development in an effort to provide the most useful and reliable dissolved gas sensors in the marketplace. Many of our customers face unique challenges in their research, leading to active involvement of PSI engineers. The combined knowledge and experience of the PSI team allows us to face these challenges and respond with innovative and practical solutions.

Engineers and scientists at PSI are currently involved in:
  • improving all aspects of our current instrument designs
  • developing gas sensors for measuring a broader range of dissolved gases
  • improving anti-fouling techniques
  • developing self-cleaning in-line filters
  • designing more versatile controllers and data loggers.