YSI EXO 3S Multiparameter sonde
EXO3s Multiparameter Water Quality Sonde
The EXO3s is a compact, externally powered multiparameter water quality sonde built for long-term unattended monitoring in demanding environments. Combining rugged durability, advanced anti-fouling technology, and flexible sensor integration, the EXO3s delivers reliable, high-quality data for continuous environmental monitoring.
With five universal sensor ports, including a central anti-fouling wiper port, an optional depth sensor, and a lighter, shorter design than the battery-powered EXO3, the EXO3s is ideal for fixed monitoring stations and applications where external power is available.
Please Note: External power is required for operation. For a battery-powered version, see the EXO3. This listing is for the instrument only. Cables, sensors, and accessories are sold separately.
Built for Long-Term Reliability
Engineered for harsh environments, the EXO3s features corrosion-resistant titanium construction, fully sealed laser-welded sensors, and a durable high-impact housing for dependable performance in remote and demanding deployments.
Its low power draw, large internal memory, and anti-fouling capabilities allow autonomous deployments for over three months.
Key durability features include:
Corrosion-resistant titanium sensors and bulkhead
Fully sealed, laser-welded titanium sensors and wiper
Wet-mate neoprene connectors for secure deployment
High-impact, temperature-resistant housing
Pressure-rated to 250 metres
Mechanically and electrically isolated internal components
Patented anti-fouling technology
Protected by a 3-year warranty
Advanced Anti-Fouling Protection
The EXO3s is equipped with a high-torque central wiper with dense bristles to actively clean sensor surfaces and minimise biofouling. This helps maintain sensor accuracy and data integrity throughout long-term deployments in challenging water conditions.
Intuitive Operation & Seamless Integration
Designed for fast setup and efficient operation, the EXO3s features universal sensor ports, automatic sensor recognition, guided calibration, and SmartQC™ quality assurance to simplify deployment and maintenance.
Users can view live data directly using the EXO Handheld or the Kor Mobile App, while easy integration with remote telemetry systems enables real-time monitoring and remote access.
Comprehensive Water Quality Monitoring
The EXO3s supports a wide range of water quality parameters, including:
Temperature
Conductivity / Specific Conductivity / NLF Conductivity
Salinity
Resistivity
Total Dissolved Solids (TDS)
Water Density
Dissolved Oxygen (DO)
Local DO
pH
ORP
Turbidity
Total Suspended Solids (TSS)
fDOM
Total Algae (Chlorophyll, Phycocyanin, Phycoerythrin)
ISE Ammonium / Ammonia / Chloride / Nitrate
UV Nitrate
Rhodamine WT
Depth
Vertical Position
Absolute Pressure
Suitable Applications
The EXO3s is ideal for a broad range of water monitoring applications, including:
Surface water (rivers, lakes, streams)
Coastal, estuarine, and marine systems
Source and drinking water
Stormwater monitoring
Groundwater
Aquaculture
Wastewater treatment
Industrial and urban water systems
Other EXO Sonde Options
Explore the full EXO sonde range from YSI:
EXO1 – 4 sensor ports with internal battery compartment (EXO1s available for external power)
EXO2 – 7 sensor ports with central wiper and internal battery compartment (EXO2s available for external power)
EXO3 – 5 sensor ports with internal battery compartment (EXO3s available for external power)
Lightweight, durable, and optimised for externally powered deployments, the EXO3s is a reliable solution for high-quality long-term water quality monitoring.
Depth Rating | 250 m (820 ft) |
Materials | Xenoy®, Lexan®, titanium, 316 stainless steel |
Internal Logging Memory Capacity | >1,000,000 logged readings, 512 MB memory |
Software | Kor Software |
Application | Kor Desktop, Kor Mobile |
Power Requirements | 9 - 16 VDC |
Communciations | Sonde: Bluetooth (Wireless); RS-485, SDI-12 (Field Cable) |
Operating Temperature | -5 to 50°C (23 to 122°F) |
Storage Temperature | -20 to 80°C (-4 to 176°F) |
Diameter | 7.62 cm (3.00 in) |
Length | 42.87 cm (16.88 in) |
Weight | 1.06 kg (2.34 lbs) |
Sample Rate | Up to 4 Hz |
Sensor Ports | 5 (4 Sensors + 1 Central Wiper) |
Anti-Fouling | With a central wiper occupying a sensor port |
Waterproof | Yes |
User Calibration | Yes |
Languages | English, Spanish, French, Japanese, German, Chinese |
Warranty: 3 yrs | Sonde; handheld |
Warranty: 2 yrs | Cables; conductivity/temperature and optical sensors; electronics base for pH, pH/ORP, ammonium, chloride, and nitrate sensors |
Warranty: 1 yr | Optical DO cap and replaceable reagent modules for pH and pH/ORP sensors |
Warranty: 3 mos | Replaceable reagent modules for ammonium, chloride, and nitrate sensors |
Ammonium | Ammonium Sensor | 0 to 200 mg/L-N (0 to 30˚C) | ±10% of reading or 2 mg/L-N, w.i.g. | T63<30 sec | 0.01 mg/L |
Barometric Pressure | Integral Barometer | 375 to 825 mmHg | ±1.5 mmHg from 0 to 50°C | - | 0.1 mmHg |
Blue-green Algae, | Total Algae Sensor SKU: 599102-01 | 0 to 100 μg/L; | Linearity: r2 >0.999 for serial dilution of Rhodamine WT solution across full range | T63<2 sec | 0.01 μg/L; |
Blue-green Algae, | Total Algae Sensor SKU: 599103-01 | 0 to 280 μg/L; | Linearity: r2 >0.999 for serial dilution of Rhodamine WT solution acriss full range | T63<2 sec | 0.01 μg/L; |
Chloride | Chloride Sensor | 0 to 1,000 mg/L-Cl (0 to 30˚C) | ±15% of reading or ±5 mg/L-Cl, w.i.g. | T63<30 sec | 0.01 mg/L |
Chlorophyll | Total Algae Sensor | 0 to 400 μg/L Chl; | Linearity: r2 >0.999 for serial dilution of Rhodamine WT solution across full range | T63<2 sec | 0.01 μg/L Chl; |
Conductivity1 | Wiped Conductivity / Temperature Sensor | 0 to 100 mS/cm | ±1% of reading or 2 µS/cm, w.i.g | T95<30 sec | 0.001 to 0.01 mS/cm (range dependent) |
Depth - 10 m | Integral, Non-vented Depth Sensor3 | 0 to 10 m | ±0.04% FS (±0.004 m or ±0.013 ft) | T63<2 sec | 0.001 m (0.001 ft) |
Depth - 100 m | Integral, Non-vented Depth Sensor3 | 0 to 100 m | ±0.04% FS (±0.04 m or ±0.13 ft) | T63<2 sec | 0.001 m (0.001 ft) |
Depth - 250 m | Integral, Non-vented Depth Sensor3 | 0 to 250 m | ±0.04% FS (±0.10 m or ±0.33 ft) | T63<2 sec | 0.001 m (0.001 ft) |
Dissolved Oxygen, % air saturation | Optical Dissolved Oxygen Sensor | 0 to 500% | 0 to 200%: ±1% of reading or 1% saturation, w.i.g.; | T63<5 sec5 | 0.1% air saturation |
Dissolved Oxygen, mg/L | Optical Dissolved Oxygen Sensor | 0 to 50 mg/L | 0 to 20 mg/L: ±0.1 mg/L or 1% of reading, w.i.g.; | T63<5 sec5 | 0.01 mg/L |
fDOM | fDOM Sensor | 0 to 300 ppb Quinine Sulfate equivalents (QSU) | Linearity: r2 > 0.999 for serial dilution of 300 ppb QS solution | T63<2 sec | 0.01 ppb QSU |
Level, Vented - 10 m | Integral Vented Level Sensor | 0 to 10 m (0 to 33 ft) | ±0.03% FS (±0.003 m or ±0.010 ft) | T63<2 sec | 0.001 m (0.001 ft) |
Nitrate | Nitrate Sensor | 0 to 200 mg/L-N (0 to 30˚C) | ±10% of reading or ±2 mg/L-N, w.i.g. | T63<30 sec | 0.01 mg/L |
pH | pH Sensor | 0 to 14 units | ±0.1 pH units within ±10˚C of calibration temperature; | T63<3 sec8 | 0.01 units |
ORP | pH/ORP Sensor | -999 to 999 mV | ±20 mV in Redox standard solution | T63<5 sec6 | 0.1 mV |
Temperature | Wiped Conductivity / Temperature Sensor | -5 to 50°C | ±0.2°C2 | T95<30 sec | 0.001 °C |
Turbidity9 | Turbidity Sensor | 0 to 4000 FNU | 0 to 999 FNU: 0.3 FNU or ±2% of reading, w.i.g.; | T63<2 sec | 0 to 999 FNU: 0.01 FNU |
Salinity | Calculated from Conductivity and Temperature11 | 0 to 70 ppt | ±1.0% of reading or 0.1 ppt, w.i.g. | T63<2 sec | 0.01 ppt |
Specific Conductance | Calculated from Conductivity and Temperature11 | 0 to 200 mS/cm | ±0.5% of reading or 0.001 mS/cm, w.i.g. | - | 0.001, 0.01, 0.1 mS/cm |
Total Dissolved Solids (TDS) | Calculated from Conductivity and Temperature11 | 0 to 100,000 mg/L | Not Specified | - | Variable |
Total Suspended Solids (TSS) | Calculated from Turbidity and user reference samples | 0 to 1500 mg/L | Not specified | T63<2 sec | Variable |
**Specifications indicate typical performance and are subject to change. All sensors have a depth rating to 250 m (820 ft), except shallow and medium depth sensors, ammonium, chloride, and nitrate. Accuracy specification is attained immediately following calibration under controlled and stable environmental conditions. Performance in the natural environment may vary from quoted specification.
w.i.g. = whichever is greater
EXO sensors are not compatible with YSI 6-Series sondes, sensors, or handheld.
1Outputs of specific conductance (conductivity corrected to 25˚C) and total dissolved solids are also provided. See Calculated Parameters and footnote 11.
2 Temperature accuracy traceable to NIST standards
3Accuracy specifications apply to conductivity levels of 0 to 100,000 μS/cm.
4 Relative to calibration gases
5 When transferred from air-saturated water to stirred deaerated water
6 When transferred from water-saturated air to Zobell solution
7Within the environmental pH range of pH 4 to pH 10.
8On transfer from water-saturated air to rapidly stirred air-saturated water at a specific conductance of 800 μS/cm at 20˚C; T63<5 seconds on transfer from water-saturated air to slowly-stirred air-saturated water.
9 Calibration: 1-, 2-, or 3-point, user-selectable
10 Performance based on 3-point calibration done with YSI AMCO-AEPA standards of 0, 124, and 1010 FNU. The same type of standard must be used for all calibration points.
11 Values are automatically calculated from conductivity according to algorithms found in Standard Methods for the Examination of Water and Wastewater (Ed. 1989).
Xenoy is a trademark of SABIC Innovative Plastics IP BV.
EXO Bluetooth modules comply with Part 15C of FCC Rules and have FCC, CE Mark and C-tick approval. Bluetooth-type approvals and regulations can be country specific. Check local laws and regulations to insure that the use of wireless products purchased from Xylem are in full compliance.