making ocean carbonate instruments since 1999.
The Autonomous Flow Through Instrument pH (AFT-pH) has the following characteristics:
  • Measures pH in the 7-9 range (Salinity 25-40)
  • Designed to accurately measure pH of flowing seawater or individual samples
  • Based on the same technology as the SAMI-pH
  • Packaged to be plumbed into a sea line on a research vessel or can be used for bottle samples in the lab.
  • Once programmed and launched, the AFT-pH can run autonomously or while connected to a PC if real-time data is required
  • Logs own data
  • Can support other external instruments
  • Uses a highly accurate colorimetric reagent method
  • Accuracy and precision: +/- 0.003 pH units and < 0.001 pH units
  • Long term drift < 0.001 pH units over 6 months
AFT-pH Performance Parameters 
pH range  7-9
Salinity range* 25-40
Response time  3 minutes
Duration of use 15,000 measurements on one reagent bag
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 of housing 25.4 x 30.5 x 14 cm
Weight in air/seawater  7 kg
* Extended range possible, please contact us with questions. If salinity varies significantly (+/-1) the AFT can use thermo-salinograph data for correction.