pH/O.R.P. (Redox) Sensor 
SBE 27

DESCRIPTION

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 up to 1200 meters (3,900 ft) deep. The replaceable pH probe is permanently sealed and is supplied with a soaker bottle attachment to prevent the reference electrode from drying out during storage.

The sensor elements and their interface electronics are modular and self-contained, providing easy installation, service, and calibration. 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 SEALOGGER). Power / signal interface cables and mounting hardware are available separately.

The SBE 27 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 the pH reference junction to produce pH and O.R.P. dependent output voltages. Computation of pH and O.R.P. in engineering units is typically done using our SEASOFT^© V2 software.

Sea-Bird calibrates the pH sensor against precision buffer solutions (4, 7, 10, pH ± 0.02 pH). The extremely stable O.R.P. circuitry is calibrated at the factory and does not require subsequent calibrations. These calibration results are tabulated on a certificate furnished with each sensor.

SPECIFICATIONS

Power required: 6 - 24 VDC, 10 mA

Signal outputs: 0 to +5 V

Operating depth: 1200 meters (3,900 ft)

Weight:

• 0.7 kg (1.6 lbs) in air
• 0.3 kg (0.7 lbs) in water

Materials: Anodized aluminum (6061-T6), stainless steel, plastic (acetal copolymer)

ADDITIONAL INFORMATION / LINKS:

Documentation -- manual, photos, technical papers, application notes, etc.

• Print version of this specification sheet / brochure
• Application Notes:
  - 18-1: SBE 18, 27, and 30 and AMT pH Sensor Calibration
  - 19: SBE 27 or 30 Oxidation Reduction Potential (O.R.P.) Sensor
  - 71: Desiccant Use and Regeneration (drying)
  - 76: pH or pH/O.R.P. Sensors and Moored Applications

Sales Information -- options, accessories, cables, mount kits, spares, etc.

• Configuration options & accessories:
  - Details for SBE 27
  - Listing for all products
• Cables
• Mount kits
• Spare parts

Links to Other Instruments of Interest

• CTDs that accept SBE 27 integration:
  - SBE 9plus -- premium CTD
  - SBE 25 -- CTD
  - SBE 19plus V2 -- small, economical CTD