making ocean carbonate instruments since 1999.
SAMI-pH - Ocean pH Sensor
  • Measures pHT (total hydrogen scale) in the marine pH range of 7-9
  • Uses a highly accurate colorimetric reagent method
  • System does not suffer from the drift that plagues most electrode based pH probes
  • Designed to provide researchers with valuable in-situ time series data at depths up to 600 meters
  • 234-day deployment capability (hourly measurements, 25C)
  • Extra battery package allows the SAMI-pH to run for more than a year
  • Can support up to 3 external instruments (e.g., PAR, dissolved oxygen, chlorophyll fluorometer, CTD)
  • Supports Seabird underwater inductive modems or external loggers via RS-232


SAMI-pH Performance Parameters

pH range  7-9
Salinity range* 25-40
Response time  3 minutes
Accuracy (based on CRM intercomparison)  +/- 0.003 pH units
Precision <0.001 pH units
Long term drift <0.001 pH units over 6 months
Thermistor accuracy, precision 0.1° C,  +/- 0.01º C
Dimensions (housing length, diameter - single battery)  55 cm, 15.2 cm
Weight in air/seawater  7.6 kg / 1.1 kg
* Extended range possible, please contact us with questions.