News Release: YSI’s EXO Breaks the Sonde Barrier

By on March 13, 2012

Advanced water-quality monitoring instruments for demanding environments

March 13, 2012 — YSI has used its long experience in water quality monitoring to develop the ultimate multiparameter sondes for challenging marine and freshwater conditions.

Users can choose the new EXO1 sonde, with ports for 4 sensors, or the new EXO2 sonde, with 6 ports and a central anti-fouling wiper.

Parameters include: Temperature, Conductivity, Depth, Dissolved Oxygen, pH, ORP, Total Algae (Blue-green Algae and Chlorophyll), Turbidity, and fDOM, plus 4 calculated parameters.

Key Benefits

  • CTD plus 3-5 additional sensors in one small package
  • High-accuracy sensors with on-board memory
  • Wireless communications
  • Seamless integration into marine, estuarine, freshwater and ground water monitoring systems

Smart Sondes and Sensors

“EXO was designed to be extremely versatile, allowing the user to configure a sonde for different applications in minutes. The key to this versatility is the smart sensors and smart ports,” explains Rob Ellison, YSI Director of R&D. “Each smart port is identical and automatically recognizes any EXO sensor so sensor payloads are designed by the user.”

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

For long-term monitoring programs, the data collected by EXO sensors are compatible with historic data from YSI 6-Series sensors, helping users to maintain a consistent record of measurements.


EXO sensors and sondes are tested in a variety of rigorous field conditions as well as lab conditions to ensure accuracy and response times.

“With YSI’s focus on building monitoring systems for natural environments, our sensor specifications are based on the entire range of environmental extremes that a system could encounter in nature. Sensors have fast response times for profiling and sampling, and a depth rating of 250 meters,” notes EXO product manager Tim Finegan.

Also, a new metrology system specifically for EXO offers improved accuracy of conductivity and temperature sensors to better address oceanographic challenges.


  • Long-term continuous monitoring
  • Vertical profiling
  • Underway monitoring
  • Integration into remote monitoring platforms
  • Source Water monitoring
  • Ground Water monitoring
  • Stormwater monitoring
  • Dredging
  • Spot sampling
  • Stand-alone sensors


  • Enhanced software
  • Handheld display
  • Multiple data output options, including DCP, USB, and Bluetooth wireless communication

The EXO platform is jointly distributed by YSI and WTW (brands of Xylem Inc.). For more information, including features and product specifications, visit

Leave a Reply

Your email address will not be published. Required fields are marked *

Fondriest Environmental Monitoring Products