iSAMI-pH - Inexpensive near surface instrument

A beta version of the iSAMI-pH won the Wendy Schmidt Ocean Health XPRIZE for affordable autonomous pH instruments.  

In its current form, the i-SAMI-pH uses the same principles as the SAMI-pH, with a very compact footprint (28 cm x 6.4 cm) and at much lower cost.  The iSAMI-pH can be used for surface measurements (3 m maximum depth), can be powered externally by a user supplied power or by an optional external battery pack, and internally logs data for up to 8,000 measurements.  With accuracy better than 0.01 pH* and precision of 0.004 pH* of this instrument exceed specs of our competitor at an affordable price. 

*based on Tris buffer standards

Autonomous Flow Through Instrument (AFT)

The AFT-CO2 and AFT-pH are benchtop instruments based on the same technology as the SAMIs.  They measure either pCO₂ (carbon dioxide) or pH from a stream of water pumped through the unit.  They are typically used on research vessels or ships of opportunity to measure surface water but can also be used for benchtop measurements of discrete samples.

The AFT can also support 3 external instruments, including GPS. If connected to a computer, real-time data can be obtained.  If preferred, AFT data can be dowloaded later from the internal data logger. Programming, download and display of the data are performed by the same client software used for the SAMIs.

SuperCO₂ System

Built around a LI-COR 850 CO₂/H₂O Analyzer, the SuperCO₂ uses either a showerhead equilibrator or a membrane contactor to equilibrate a gas stream to a flowing sample stream. The unit uses a Windows based tablet running custom developed software for control, display and data collection. Once running the unit requires minimal oversight. Because it is built around an NDIR (non-dispersive infrared) gas analyzer, it has a very fast response time and can measure every 2 seconds if desired.

Using gas standards (user-supplied), the SuperCO₂ self-calibrates periodically and can also take periodic samples of ambient air.

The SuperCO₂ can log data from a Seabird thermosalinograph (TSG) and also has capability of monitoring other analog output sensors by special order.

Submersible Autonomous Moored Instrument (SAMI)

Ocean pH and CO₂ Sensors

Developed by Dr. Mike DeGrandpre at Woods Hole in the mid 90's, the Submerisble Autonomous Moored Instrument for carbon dioxide (SAMI-CO2) uses patented technology (US Patent 7,026,165) to measure pCO₂.  Sunburst Sensors has exclusive license to this technology and has been producing the instrument since 1999.  The SAMI-pH joined the product line in 2007 utilizing similar technology.  Both instruments were completely redesigned in 2010. 

The SAMIs are deployable to 600 m and can run for over a year taking hourly measurements*. They can support up to 3 external instruments such as PAR, dissolved O₂, chlorophyll fluorometer or CTD. Though they log their own data, the SAMIs can be configured to communicate with the Seabird Inductive Modem system or external data loggers.

A titanium-housed SAMI-pH won first place in the accuracy category for the Wendy Schmidt Ocean Health XPRIZE

*The SAMI-pH requires a supplemental battery pack for this number of measurements