title: An Autonomous Sensor and Telemetry System for Low-Level pCO(2) Measurements in Seawater.
abstract: The measurement of low-level dissolved CO(2) using a fiber-optic sensor is described. The sensor, based on the Severinghaus CO(2) electrode principle, consists of a CO(2)-sensitive bicarbonate buffer solution containing the pH-sensitive fluorescent dye carboxy-SNAFL-1 immobilized at the end of an optical fiber using a gas-permeable membrane. The sensor is used in a ratiometric mode and has a reversible working dynamic range between 200 and 1000 ppm pCO(2) and a sensitivity ±1 ppm. Results are presented for the sensor calibration, effects of temperature, and response time characteristics. An integrated measurement system with electrooptic and data acquisition modules coupled to a satellite transmission system was tested in Vineyard Sound, MA, and data are presented that demonstrate continuous monitoring of pCO(2) in surface seawater.
authors.affiliation: Max Tishler Laboratory for Organic Chemistry, Department of Chemistry, Tufts University, 62 Talbot Avenue, Medford, Massachusetts 02155.
authors.forename: M B
authors.initials: MB
authors.lastname: Tabacco
authors.forename: M
authors.initials: M
authors.lastname: Uttamlal
authors.forename: M
authors.initials: M
authors.lastname: McAllister
authors.forename: D R
authors.initials: DR
authors.lastname: Walt