YSI EXO Conductivity & Temperature Sensor
Features
- 0 to 200 mS/cm measurement range
- T63<2 sec response time
- ±0.5% of reading or 0.001 mS/cm accuracy from 0 to 100
- Free ground shipping
- Expedited repair and warranty service
- Lifetime technical support
- More
Overview
The YSI EXO conductivity & temperature sensor is a digital smart sensor featuring welded titanium construction and wet-mateable connectors. The sensor provides accurate and fast temperature data and enables temperature compensation for other EXO probes. Conductivity data is used to calculate salinity, non-linear function (nLF) conductivity, specific conductance, and total dissolved solids, and compensate for changes in the density of water (as a function of temperature and salinity) in depth calculations if a depth sensor is installed.
Temperature Thermistor
The temperature sensor uses a highly stable and aged thermistor with low-drift characteristics. The thermistor’s resistance changes with temperature. The measured resistance is then converted to temperature using an algorithm. The temperature sensor receives a multi-point NIST traceable wet calibration, and the accuracy specification of 0.01˚C is valid for the expected life of the probe. No calibration or maintenance of the temperature sensor is required, but accuracy checks can be conducted.
Conductivity Electrodes
The conductivity sensor uses four internal, pure-nickel electrodes to measure solution conductance. Two of the electrodes are current-driven, and two are used to measure the voltage drop. The measured voltage drop is then converted into a conductance value in milliSiemens (millimhos). To convert this value to a conductivity value in milliSiemens per cm (mS/cm), the conductance is multiplied by the cell constant that has units of reciprocal cm (cm-1). The cell constant for the conductivity cell is approximately 5.5/cm ±10%. For most applications, the cell constant is automatically determined (or confirmed) with each deployment of the system when the calibration procedure is followed.
Temperature Compensation
EXO sensors have internal thermistors for quality assurance purposes. Turbidity uses the internal thermistor for temperature compensation, while all other EXO sensors reference the C/T probe for temperature compensation. To display and log temperature, a C/T probe must be installed in an EXO sonde. Thermistor readings are logged in the sonde’s raw data–viewable in KOR software–but are not included in data exported to Excel.
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