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pH Sensors

SeaFET Ocean pH Sensor
pH (potential Hydrogen) is a measurement of the level of acids and bases in water. Our pH sensors have been used extensively to research ocean acidification, coral reefs, coastal marine biology, and to conduct environmental monitoring.

Ocean acidification is the ongoing decrease in the pH of the Earth’s oceans, caused by the uptake of atmospheric carbon dioxide (CO2) as water and air mix at the water’s surface. Oceans, rivers, and lakes absorb roughly one third of human-created CO2 emissions (22 million tons) each day. Stress on marine life due to acidification (lowering the pH) leads to dying or severely affected ecosystems.

High-resolution in-situ measurements of pH in the ocean are now possible with innovative adaptations of ion-sensitive field-effect transistors (ISFET). Oceanographic instruments based on ISFET technology have been in development for more than a decade, but earlier instruments had depth limitations or significant drift and environmental constraints that limited their adoption. Sea-Bird Scientific’s line of ocean pH sensors use Honeywell’s innovative ion-sensitive field effect transistor (ISFET) technology to provide a level of precision and stability not before possible.

The SeaFET™ V2 Ocean pH sensor uses the ISFET technology for stable, long-term pH measurements in salt water. The pH sensor has been used extensively around the globe for ocean acidification research, coral reef research, coastal marine biology and environmental monitoring. The SeaFET™ V2 Ocean pH sensor is fully autonomous with internal power, sample scheduling and data logging capabilities. The advantages of the ISFET include robustness, stability and precision that make it suitable for ocean pH measurement at low pressure.


Navis BGCi + pH Float

Autonomous profiling float with Sea-Bird CTD, Dissolved Oxygen sensor, MCOMS fluorometer/backscattering sensor and Float pH sensor, which adapts the field-tested MBARI/SIO/Honeywell Deep-Sea DuraFET technology to measure pH.

SeaFET™ V2 Ocean pH Sensor

ISFET-based pH sensor for high accuracy, resolution, and long-term stability.

SeapHOx™ V2 Ocean CT(D)-pH-DO Sensor

ISFET-based pH sensor for high accuracy, resolution, and long-term stability. Integrated CTD provides temperature, salinity, pressure, and dissolved oxygen data, with pumped flow and anti-fouling technology.