EXO3 Multiparameter Sonde

EXO Sonde Overview | Multiparameter Water Quality

Explore common features and individual options of the different EXO Multiparameter Water Quality Sondes

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Multiparameter Water Quality Sonde with 5 sensor ports (including a central wiper port), optional depth sensor, and battery compartment

EXO Multiparameter Sondes — the best-in-class platform for the highest quality data. EXO's dynamic range of smart sensors provide comprehensive multiparameter water quality data while SmartQC ensures proper calibrations and top sensor performance. You can be confident in your extended deployments thanks to EXO's tough materials and unmatched anti-fouling technology.

Instrument Only. Cables, probes/sensors, and accessories sold separately.

  • Overview


    The parameters you need, without the features you don't!

    Offering the greatest value of any sonde available on the market, EXO3 combines the maneuverability of the EXO1 with the powerful antifouling wiper of the EXO2.

    The EXO advanced water quality monitoring platform includes the versatile multiparameter EXO3 sonde for oceanographic, estuarine, or surface water applications.

    EXO3 is a purpose-built sonde for monitoring major water quality parameters, including: pH, conductivity, temperature, turbidity, and dissolved oxygen.

    Key Benefits

    exo multiparameter sonde data datasonde

    Highest Data Quality
    Onboard monitoring systems verify sensor operation

    Multiparameter Monitoring
    5 universal ports for allow for any combination of smart sensors or the central wiper

    exo anti-fouling antifouling

    Industry-leading Anti-fouling
    Best-in-class wiper technology

    Titanium Components
    The toughest grade parts guarantee operation well into the future 

    Seamless Integration
    EXO can plug-and-play into marine, estuarine, freshwater, and groundwater monitoring systems

    Additional Benefits Only from EXO3

    Maintenance Special
    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.

    YSI Integrated Systems
    Integral SDI-12 communications makes it ideal for existing data collection 
    platforms and installations. (Including replacement of 6-Series sondes.)

    Smart Sondes and Sensors
    EXO is an extremely versatile instrument, allowing the user to automatically configure a sonde with different sensors for different applications in minutes

    Smart Sensor Options:
    • Conductivity/Temperature (wiped and non-wiped)
    Dissolved Oxygen
    • ISEs (Ammonium, Chloride, and Nitrate)
    • pH (guarded and unguarded)
    • pH & ORP (guarded and unguarded)
    NitraLED (UV Nitrate)
    • Total Algae (Chlorophyll + Phycocyanin and Phycoerythrin)

    Other Available Parameters
    • Absolute Pressure
    • Ammonia
    • Depth
    • DO% Local
    • Guage Pressure
    • nLF Conductivity
    • PAR
    • Resistivity
    • Salinity
    • Specific Conductivity
    • Total Dissolved Solids
    • Total Suspended Solids
    • Water Density

    EXO sondes and sensors are 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 smart sensor 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 anti-fouling systems protect data integrity
    • Low power consumption extends underwater deployments

    Monitoring Made Mobile
    EXO makes it easy to view data in the field. The EXO Handheld offers a dedicated, streamlined interface to EXO sondes. EXO GO uses Bluetooth to connect any Windows OS device to a submerged EXO sonde.

    Other EXO Sonde Options
    EXO3s Sonde offers the same features as the EXO3, but without the battery compartment
    EXO1 Sonde (4 ports) — also available without battery compartment
    EXO2 Sonde (7 ports including Central Wiper port) — also available without battery compartment

    Add an EXO Factory Service Plan
    to your next sonde purchase and have the peace of mind that your new instrument is covered. Use today’s budget to protect your investment for years to come!

    YSI Integrated Systems

    The EXO sondes are a key component of a complete, unattended long-term water quality monitoring system from our Integrated Systems & Services group.

    EXO University

    Learning a new water quality platform can be a challenging process. Accelerate through the learning curve with our on-demand training program. Join us at YSI University!

    Kor Software

    KorEXO Software makes it easy to manage EXO instrumentation and water quality data. Calibrate sensors, set up long-term deployments, and ensure equipment is operating at peak performance using the traditional Desktop Software or the new Kor Mobile App!

  • Specifications
    Connectivity / Communications Sonde: Bluetooth wireless technology, RS-485, and integral SDI-12 Output Options with Adapters: USB, RS-232, or Modbus
    Depth Rating 0 to 250 m (0 to 820 ft)
    Desktop Software Compatible KorEXO
    Flow Cell Yes

    Fresh, sea or polluted water

    Memory 512 MB total memory; >1,000,000 logged readings
    Monitoring Yes
    Multiparameter Yes
    Operating Temperature -5 to 50 °C (23 to 122 °F)
    Power 2 Alkaline Batteries
    Sampling Yes

    Diameter: 7.62 cm (3.00 in)  Length: 58.67 cm (23.1 inc)

    Smart Sensors / Ports 5 sensor ports (4 ports available when central wiper in use) Peripheral ports: 1 power communication port
    Storage Temperature -20 to 80 °C (-4 to 176 °F). Exception: 0 to 60 °C (32 to 140 °F) for pH and pH/ORP sensors
    User Calibratable Yes
    Waterproof Yes
    Weight 2.00 kg (4.41 lbs) with a full payload of 4 probes, 1 wiper, and probe guard installed
    EXO3 Specifications  
    Battery Life 60 days*
    Communications Computer Interface: Bluetooth wireless technology (between sonde and handheld or computer with KOR software), USB
    Output Options: SDI-12 (native output), USB with signal output adapter (SOA); & RS-232 with DCP-SOA.
    Diameter 7.62 cm (3.00 in)
    Length 58.61 cm (23.07 in)
    Peripheral Ports 1 power communication port; 1 auxiliary port for third-party sensors (future functionality; not active yet)
    Sample Rate Up to 4 Hz
    Sensor Ports 5 (4 ports available when central wiper used)
    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
    Weight 2.00 kg (4.41 lbs)

    *Typically 60 days at 20˚C at 15-minute logging interval; temperature/conductivity, pH/ORP, DO, total algae, and turbidity sensors installed with central wiper that rotates once per logging interval on EXO3. Battery life is heavily dependent on sensor configuration.

    EXO Parameter Measured Sensor** Range Accuracy Response Resolution
    (freshwater only)
    Ammonium Sensor
    Ammonia with pH sensor
    SKU: 599710
    0 to 200 mg/L (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;
    0 to 100 RFU;
    Linearity: R2 >0.999 for serial dilution of Rhodamine WT solution from 0 to 100 μg/mL BGA-PC equivalents T63<2 sec 0.01 μg/L;
    0.01 RFU
    Blue-green Algae,
    Total Algae Sensor 0 to 280 μg/L;
    0 to 100 RFU;
    Linearity: R2 >0.999 for serial dilution of Rhodamine WT solution from 0 to 280 μg/mL BGA-PE equivalents T63<2 sec 0.01 μg/L;
    0.01 RFU
    (freshwater only)
    Chloride Sensor
    SKU: 599711
    0 to 18000 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;
    0 to 100 RFU
    Linearity: R2 >0.999 for serial dilution of Rhodamine WT solution from 0 to 400 μg/L Chl a equivalents T63<2 sec 0.01 μg/L Chl;
    0.01 RFU
    Conductivity1 Conductivity / Temperature Sensor
    SKU: 599870
    0 to 200 mS/cm 0 to 100: ±0.5% of reading or 0.001 mS/cm, w.i.g.;
    100 to 200: ±1% of reading
    T63<2 sec 0.0001 to 0.01 mS/cm (range dependent)
    Depth - 10 m Integral, Non-vented Depth Sensor3 0 to 10 m
    (0 to 33 ft)
    ±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 to 328 ft)
    ±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 to 820 ft)
    ±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
    SKU: 599100-01
    0 to 500%
    air saturation
    0 to 200%: ±1% of reading or 1% saturation, w.i.g.;
    200 to 500%: ±5% of reading 4
    T63<5 sec5 0.1% air saturation
    Dissolved Oxygen, mg/L Optical Dissolved Oxygen Sensor
    SKU: 599100-01
    0 to 50 mg/L 0 to 20 mg/L: ±0.1 mg/L or 1% of reading, w.i.g.;
    20 to 50 mg/L: ±5% of reading 4
    T63<5 sec5 0.01 mg/L
    fDOM Sensor
    SKU: 599104-01
    0 to 300 ppb Quinine Sulfate equivalents (QSU) Linearity: R2 > 0.999 for serial dilution of 300 ppb QS solution
    Detection Limit: 0.07 ppb QSU
    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)
    (freshwater only)
    Nitrate Sensor
    SKU: 599709
    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
    SKU:599701 guarded, 599702 unguarded

    pH/ORP Sensor
    SKU:599705 guarded, 599706 unguarded
    0 to 14 units ±0.1 pH units within ±10˚C of calibration temp;
    ±0.2 pH units for entire temp range7
    T63<3 sec8 0.01 units
    ORP pH/ORP Sensor
    SKU:599705 guarded
    599706 unguarded
    -999 to 999 mV ±20 mV in Redox standard solution T63<5 sec6 0.1 mV
    Temperature Conductivity / Temperature Sensor
    SKU: 599870
    -5 to 35°C
    35 to 50°C
    T63<1 sec 0.001 °C
    Turbidity9 Turbidity Sensor
    SKU: 599101-01
    0 to 4000 FNU, NTU 0 to 999 FNU: 0.3 FNU or ±2% of reading, w.i.g.;
    1000 to 4000 FNU: ±5% of reading10
    T63<2 sec 0 to 999 = 0.01 FNU, NTU;
    1000 to 4000 = 0.1 FNU, NTU
    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 .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
    Cal constant range
    0.30 to 1.00
    (0.64 default)
    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.

  • Accessories

    EXO GO

    Wireless communication device for the EXO sondes.

    EXO Handheld Display

    Enhanced interface for calibrating and data logging with the EXO platform

    EXO Wiped Conductivity & Temperature Sensor

    EXO Wiped Conductivity & Temperature Digital Smart Sensor

    EXO Optical Dissolved Oxygen Smart Sensor

    EXO Optical Dissolved Oxygen Digital Smart Sensor

    EXO pH Smart Sensor

    EXO pH Digital Smart Sensor (Unguarded)

    EXO pH & ORP Smart Sensor

    EXO pH & ORP Digital Smart Sensor (Unguarded)

    EXO Turbidity Smart Sensor

    EXO Turbidity Digital Smart Sensor

    EXO Central Wiper

    Anti-fouling Wiper for the EXO2 and EXO3 Platforms

    EXO Total Algae PC Smart Sensor

    EXO Total Algae Phycocyanin Digital Smart Sensor - Freshwater

    EXO Total Algae PE Smart Sensor

    EXO Total Algae Phycoerythrin Digital Smart Sensor - Saltwater

    EXO NitraLED UV Nitrate Sensor

    EXO NitraLED UV Nitrate Sensor for Freshwater Environments

    EXO fDOM Smart Sensor

    EXO Fluorescent Dissolved Organic Matter Digital Smart Sensor

    EXO Ammonium Smart Sensor

    EXO Ammonium Digital Smart Sensor (ISE)

    EXO Nitrate Smart Sensor

    EXO Nitrate Digital Smart Sensor (ISE)

    EXO Chloride Smart Sensor

    EXO Chloride Digital Smart Sensor (ISE)

    EXO Rhodamine Sensor

    EXO Rhodamine Digital Smart Sensor

    EXO DCP Signal Output Adapter 2.0

    For integrating a data logger and telemetry system with an EXO sonde.

    EXO Modbus Signal Output Adapter

    For integrating an EXO Sonde into a SCADA system.

    EXO Flying Lead Cable

    Connects EXO Sonde to DCP Signal Output Adapter

    EXO Vented Flying Lead Cable

    Connects EXO Sonde to DCP Signal Output Adapter in Vented Applications

    EXO Field Cable

    Field Cable

    EXO Central Wiper Brush Kit

    Replacement Wiper

    EXO Wiper Brush Guard Replacement Kit

    Replacement guards for EXO2 central wiper

    EXO pH Sensor Replacement Module

    Unguarded pH Module

    EXO pH & ORP Sensor Replacement Module

    Unguarded pH/ORP Module

    EXO Ammonium Sensor Replacement Module

    Shallow Freshwater Only

    EXO Nitrate Sensor Replacement Module

    Shallow Freshwater Only

    EXO Chloride Sensor Replacement Module

    Shallow Freshwater Only

    EXO Cable Couplers

    Brass or Titanium

    EXO Anti-fouling C/T Screen

    Copper probe screen

    EXO2 / EXO3 Anti-Fouling Guard

    Copper-alloy guard

    Anti-Fouling Copper Tape

    Copper tape provides biofouling protection

    Anti-Fouling C-Spray

    Non-Toxic Biofouling Inhibitor

    EXO2 / EXO3 Hard Sided Wheeled Carrying Case

    Hard Sided Wheeled Carrying Case

    EXO2 / EXO3 Sonde Weight Kit

    Profiling Accessory

    EXO2 / EXO3 Replacement Bail

    Replacement Bail

    EXO Tool Kit

    Replacement Tool Kit

    EXO Sensor Retaining Nut Kit, Titanium

    Replacement sensor retaining nuts

    EXO2 Wiper Retaining Nut Kit, Titanium

    Replacement EXO2 wiper retaining nuts

    EXO2 / EXO3 Guard Assembly Kit

    EXO2 / EXO3 Probe Guard

    Krytox® Lubricant

    O-Ring grease

    EXO Wiped (C/T) Sensor, Spacing Kit

    Maintenance kit for EXO Wiped (C/T) sensor

    EXO2 / EXO3 Alignment Ring Kit

    Alignment Ring for EXO NitraLED use on EXO2 and EXO3 Sondes

    EXO NitraLED Wiper Brush Kit

    Wiper brush for EXO NitraLED UV Nitrate Sensor

    Turbidity Standard

    Turbidity Standard

    pH Buffer

    pH Buffer

    Conductivity Calibrator Solution

    Conductivity Calibrator Solution

    NitraLED Calibration Standard

    Calibration Standard for EXO NitraLED UV Nitrate Sensor

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