YSI EXO3 Multiparameter Sonde

Offering the greatest value of any sonde available in the market, EXO3 combines the maneuverability of EXO1 with the powerful antifouling wiper of the EXO2. EXO3 is a purpose-built sonde for monitoring major water quality parameters, including: pH, conductivity, temperature, turbidity and dissolved oxygen.

  • Features
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Key Benefits

  • High-accuracy sensors with on-board memory
  • Wireless communications
  • Seamless integration into marine, estuarine, freshwater and ground water monitoring systems

Smart Sondes and Sensors

Extremely versatile instrument, allowing the user to automatically configure a sonde with different sensor for different applications in minutes.


Tested in a variety of rigorous field conditions as well as lab conditions to ensure accuracy and response times

Monitor without Interruption

No matter which EXO sensors users select, other features of the sensors' design make them rugged and durable:

  • Wet-mateable connectors resist corrosion
  • Isolated components prevent short circuits
  • Welded housings and double o-rings prevent leaks
  • High-impact plastic and titanium resists breaking
  • Built-in antifouling systems protect data integrity
  • Low power consumption extends underwater deployments

EXO3 offers even more:

  • The best-priced, highest-quality sonde for baseline water quality monitoring.
  • Flexibility to switch from continuous monitoring to spot sampling with a lighter, shorter form factor.
  • Integral SDI-12 communications makes it ideal for existing data collection platforms and installations, including stations that need easy replacement of our legacy 6-Series sondes.
  • Plug-and-play design with all existing EXO platform smart sensors, including Total Algae, fDOM, and Wiped Conductivity & Temperature.
  • The best antifouling wiper in the industry, protecting your sensors for up to 90 days in the harshest conditions.