Model SBE 27 -pH/O.R.P. (Redox) Sensor

The SBE 27 pH and O.R.P. (Redox) sensor combines a pressure-balanced, glass-electrode, Ag/AgCl reference probe and platinum O.R.P. electrode to provide in-situ measurements at depths to 1200 m. The replaceable pH probe is permanently sealed and is supplied with a soaker bottle attachment that prevents the reference electrode from drying out during storage. The sensor is a modular, self-contained package that is easy to install, service, and calibrate.

The SBE 27 is intended for use as an add-on auxiliary sensor for profiling CTDs (SBE 9plus; SBE 19, 19plus, and 19plus V2 SeaCAT; and SBE 25 and 25plus Sealogger). Power / signal interface cables and mounting hardware are available separately.

FEATURES

• Voltage output; interface electronics buffer and offset the differential voltages of the pH reference junction and
• the electrode potential (in water) between the O.R.P. electrode and pH reference junction to produce pH- and
• O.R.P.-dependent output voltages.
• Factory calibration results tabulated on a certificate furnished with each sensor:
• pH calibrated against precision buffer solutions (4, 7, and 10 pH ± 0.02 pH).
• Extremely stable O.R.P. circuitry does not require subsequent calibrations.
• 1200 m housing.
• Supplied with plastic soaker bottle and KCl soaker solution.
• Seasoft© V2 Windows software package (computation of pH and O.R.P. in engineering units).
• Five-year limited warranty.

OPTIONS

• Straight endcap for vertical mounting, or right angle endcap for horizontal mounting (for example, in an extension stand below an SBE 32 Carousel Water Sampler).
• XSG or wet-pluggable MCBH connector.

Specifications

Performance

Measurement Range: 0 to 14 pH;
±1250 mV O.R.P.
Initial Accuracy: ± 0.1 pH; ±1.0 mV O.R.P.
(stated pH accuracy achievable with frequent field calibrations)
Time Response: 1 sec pH; 10 millisec O.R.P.
(time to reach 63% of final value following a step change in pH or O.R.P.)

Electrical

Input Power: 6 - 24 VDC, 10 mA
Output Signal: 0 to +5 V

Mechanical

Housing, Depth rating, & Weight: Anodized aluminum (6061-T6), plastic (acetal copolymer)
1200 m depth rating
0.7 kg in air, 0.3 kg in water