Oceanographic Temperature Sensor
SBE 3S

Print version      Configuration options & accessories

DESCRIPTION

The SBE 3S is an enhanced version of Sea-Bird's proven SBE 3 (slow response) temperature sensor. The superior performance of the SBE 3S results from its optimized electronic design, combined with an extraordinarily precise calibration procedure and quality testing program. The SBE 3S has a time response of approximately 0.6 second, has an initial accuracy of 0.001 °C, and is typically stable to 0.002 °C per year.

Every SBE 3S is calibrated in Sea-Bird's computer-controlled calibration baths. These super-low-gradient baths produce temperature calibrations with resolution and accuracy previously unavailable commercially.

These sensors can be successfully calibrated as separate modules, because they have built-in acquisition circuits and frequency outputs. When used with a data logging system, overall system accuracy is equal to the sensor accuracy degraded only by the uncertainty in the logger's master clock. A typically small clock error of 1 ppm results in a temperature error of less than 50 µ°C.

APPLICATION

Intended primarily for use on moored and fixed-site temperature measuring systems, the SBE 3S can be used as a component in custom systems or for high-accuracy industrial and environmental temperature-monitoring applications. The low noise characteristics of the SBE 3S allow the use of hybrid frequency measuring techniques to obtain rapid sampling with very high resolution; a resolution of 40 µ°C can be readily obtained at a 6 Hz sampling rate. Depth ratings to 3400, 6800, and 10500 meters (11,100, 22,300, and 34,400 ft) are offered to suit different application requirements.

Note: See the SBE 38 for a digital oceanographic thermometer with RS-232 or RS-485 output.

OPERATION

The sensing element is a glass-coated thermistor bead, pressure-protected inside a 2.1 mm (0.083 in.) diameter thin-walled stainless steel tube. Exponentially related to temperature, the thermistor resistance is the controlling element in an optimized Wien Bridge oscillator circuit. The resulting sensor frequency is inversely proportional to the square root of the thermistor resistance and ranges from about 2 to 6 kHz, corresponding to temperatures from -5 to +35 °C.

SPECIFICATIONS

Initial Accuracy: ± 0.001 °C (NIST-traceable calibration applying over the entire oceanographic range)

Stability: 0.002 °C per year typical

Response Time [seconds]: (Time to reach 63% of final value following a step change in temperature)

• 0.580 ± 0.010 (1.0 m/s water velocity)
• 0.690 ± 0.010 (0.5 m/s water velocity)

Settling Time: < 0.5 seconds to within 0.001 °C

Power Required: 11 - 16 VDC, 25 ma

Signal Output: ± 0.5V square wave

ADDITIONAL INFORMATION / LINKS:

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

• Print version of this specification sheet / brochure
• General SBE 3 Calibration Data
• Application Notes:
  - 42: ITS-90 Temperature Scale
  - 71: Desiccant Use and Regeneration (drying)

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

• Configuration options & accessories:
  - Details for SBE 3S
  - Listing for all products
• Spare parts

Links to Other Instruments of Interest

• Other temperature sensors:
  - SBE 3F -- fast response version of SBE 3
  - SBE 3plus -- more rigorously tested and calibrated version of SBE 3F
  - SBE 35 -- laboratory standards thermometer for use in fixed point cells and depths up to 6800 m
  - SBE 35RT -- digital reversing thermometer, can be used with SBE 32 Carousel Water Sampler to measure temperature each time a bottle is fired
  - SBE 38 -- digital oceanographic thermometer with RS-232 or RS-485 output, standards-level performance
  - SBE 39plus -- high-accuracy temperature recorder with RS-232 output and internal USB interface, internal battery and non-volatile memory, plus optional pressure (NEW, February 2014)
  - SBE 39 -- high-accuracy temperature recorder with RS-232 output, internal battery and non-volatile memory, plus optional pressure
  - SBE 39-IM -- high-accuracy temperature recorder with inductive modem telemetry, internal battery and non-volatile memory, plus optional pressure
  - SBE 56 -- high-accuracy temperature recorder with internal battery, non-volatile memory, and USB upload

Specifications are subject to change without notice.

Sea-Bird Home     Phone: (+1) 425-643-9866     E-mail: seabird@seabird.com