Multiparameter Sondes
We've combined our field proven know-how with the latest innovations to the YSI water quality monitoring sonde range. They are ideal for long-term in situ monitoring and profiling projects. Features can include real-time turbidity monitoring, optical dissolved oxygen monitoring, algae monitoring, bluetooth comms and more.
- EXO Sondes
- EXO Sensors
- 6 Series Sondes
- 6 Series Sensors
- Anti-Fouling
- Handhelds

YSI EXO1 Multiparameter Sonde
Capturing accurate data in fresh water, ground water and marine aquatic environments is easy with the versatile multiparameter EXO1 sonde. Ideal for estuarine, surface water or ground water applications.
Instrument Only. Cables, probes/sensors, and accessories sold separately - please see the "Accessories" tab for details.

YSI EXO2 Multiparameter Sonde
The EXO advanced water quality monitoring platform includes the versatile multiparameter EXO2 sonde for oceanographic, estuarine, or surface water applications. Collect data to 250m with the advanced EXO2 sonde – contains six replaceable 'smart' sensors and a central wiper to clean biofouling.

YSI EXO DCP Signal Output Adapter 2.0
This adapter converts an EXO sonde signal into either SDI-12 or RS-232.
For SCADA applications, please see our EXO Modbus Adapter.
Note: This product is intended for use in a long term monitoring system. Requires an EXO Sonde, data logger, and flying lead cable to function.

YSI EXO Modbus Signal Output Adapter
This adapter converts an EXO sonde signal into a Modbus protocol over RS-232 or RS-485.
For DCP applications with a data logger, please see our EXO DCP Adapter.
Note: This product is intended for use in a long term monitoring system. Requires an EXO Sonde, data logger, and flying lead cable to function.

YSI EXO2s (Shorty) Customized Multiparameter Sonde
Go more places with YSI EXO2s (Shorty) sonde! The more maneuverable monitoring platform.
This is the EXO2s conversion service only.
EXO2 sonde, cables, probes/sensors, and accessories sold separately.
We have heard from customers who need the payload and capabilities of YSI's best-in-class EXO2 sonde, but in spaces and places that can't accommodate the EXO2. EXO2s is a customized, batteryless sonde that comes with the same warranty and capabilities as the EXO2

YSI EXO2 AUX Port Adapters
YSI’s EXO2 Auxiliary Port allows for the connection of additional sensors that enhance the measurement potential of your existing EXO2 Sonde without the need for extra data cables, conduit and civil works. red via the existing communications cable.

YSI EXO Wiped CT Conductivity & Temperature Sensor
In long-term water quality monitoring, biofouling is public enemy number one. Biofilms, barnacles, and algal growth are common culprits of poor data quality, clogging up conductivity cells and coating sensor optics. While YSI EXO2's Central Wiper can mechanically remove biofouling from other sensors to maintain data integrity over long deployment periods, the anatomy of a standard conductivity & temperature sensor makes this anti-fouling technique ineffective...until now.
Introducing the EXO Wiped Conductivity & Temperature sensor from YSI, designed with and engineered for compatibility with EXO2's Central Wiper.

YSI EXO2 Central Wiper
Monitor without interruption and reduce biofouling
The EXO2 Central Wiper occupies the central port on an EXO2 sonde, and is used to keep the payload sensor faces clean during long-term deployments. There's no escaping biofouling in underwater measurements. To keep it from interfering with data, an EXO2 sonde can be equipped with this anti-fouling wiper to prolong deployments and improve data accuracy.

YSI EXO pH & ORP Smart Sensor
The EXO guarded pH & ORP sensor is a digital smart sensor featuring welded titanium construction and wet-mateable connectors. Complete calibration in less than 15 minutes using EXO's suite of smart sensors and intuitive KOR interface software.

YSI EXO pH & ORP Sensor Replacement Module
User-replaceable tip for #599705 - EXO guarded pH/ORP sensor

YSI EXO Turbidity Smart Sensor
The EXO turbidity sensor is a digital smart sensor featuring welded titanium construction and wet-mateable connectors. Complete calibration in less than 15 minutes using EXO's suite of smart sensors and intuitive KOR interface software.

YSI EXO Total Algae PC Smart Sensor
The EXO total algae PC sensor is a digital smart sensor (chlorophyll & phycocyanin) featuring welded titanium construction and wet-mateable connectors optimized for freshwater use. Complete calibration in less than 15 minutes using EXO's suite of smart sensors and intuitive KOR interface software.

YSI EXO Optical Dissolved Oxygen Smart Sensor
The EXO optical dissolved oxygen sensor is a digital smart sensor featuring welded titanium construction and wet-mateable connectors. Complete calibration in less than 15 minutes using EXO's suite of smart sensors and intuitive KOR interface software.

YSI EXO fDOM Smart Sensor
The EXO fDOM (fluorescent dissolved organic matter) sensor is a digital smart sensor featuring welded titanium construction and wet-mateable connectors. Complete calibration in less than 15 minutes using EXO's suite of smart sensors and intuitive KOR interface software.

YSI 650 MDS Multi-Parameter Display System
Log real-time data, calibrate YSI 6-Series sondes, set-up sondes for deployment, and upload water quality data to a PC with the feature-packed YSI 650MDS (Multiparameter Display System). Designed for reliable field use, this display and data logger features a waterproof IP-67, impact-resistant case.

YSI 6600 V2 Sonde
The YSI 6600 V2 data sonde is the most comprehensive water quality monitoring equipment available with simultaneous measurement of conductivity (salinity), temperature, depth or level, pH/ORP and...

YSI 600OMS V2 Sonde
Measure optical dissolved oxygen, chlorophyll, blue-green algae, rhodamine, or turbidity in combination with temperature, conductivity and depth. Designed for use in fresh, sea or polluted waters, the 600OMS V2 data sonde utilizes the field-proven YSI sensors and incorporates innovations in water quality sensor modules that fits into the sonde body.

YSI 6920 V2 Sonde
The YSI 6920 V2 sonde is an economical water quality logging system, ideal for long-term in situ monitoring and profiling.Real-time turbidity monitoring, dissolved oxygen monitoring, algae monitoring, and more.

YSI 600LS Water Level Sonde
Measure level, flow, temperature and conductivity with the compact 600LS sonde. Rugged and waterproof, the YSI 600LS is perfect for tide gauge monitoring, wetlands level applications, ground water, estuaries, rivers, and more.

YSI 6820 V2 Multi Parameter Water Quality Sonde
The YSI 6820 V2-2 is a cost-effective data sonde for profiling and spot-checking water quality in rivers, lakes, wetlands, wells, estuaries, and coastal waters.

YSI PAR System - Photosynthetically Active Radiation
YSI offers several PAR systems that can be directly integrated into existing or new 6600 multiparameter sondes. PAR sensors are powered by the sonde and PAR data is added to the data stream of the water quality sonde.

YSI 6150 ROX Dissolved Oxygen Sensor
The YSI 6150 Reliable Oxygen Sensor (ROX) is a luminescent-based DO sensor that provides accurate long-term measurements in severe fouling and low oxygen environments.

YSI 6131 Blue-Green Algae Sensor
The YSI 6131 blue-green algae sensor monitors algal populations at natural levels in freshwater, providing an early warning for bloom conditions.

YSI 6025 Chlorophyll Sensor
Predict algae blooms and determine the nutrient loading in water with the YSI 6025 Chlorophyll Sensor.

YSI 6136 Turbidity Sensor
The YSI 6136 Turbidity Probe is a fouling-resistant, wiped sensor designed to seamlessly integrate - using no external interface hardware - with all YSI sondes that contain an optical port. The YSI 6136 provides accurate, in situ measurement of turbidity in fresh, brackish, and sea water, as well as other applications requiring highly accurate turbidity data.

YSI 6560 Temperature/Conductivity Sensor
Stable multi-probe measures conductivity and temperature levels and calculates salinity values. Thermistor readings are used to temperature-correct other parameter measurements.

YSI 6589 Fast-Response pH Sensor
Simple, accurate pH measurement in sensors designed for minimal maintenance in sampling, profiling, and long-term monitoring applications.

YSI 6425AF Anti-Fouling Chlorophyll Sensor
Predict algae blooms and determine the nutrient loading in water with the YSI 6425AF Chlorophyll Sensor.

YSI 6431AF Anti-Fouling Blue-Green Algae Sensor
The YSI 6431AF blue-green algae sensor monitors algal populations at natural levels in freshwater, providing an early warning for bloom conditions.

YSI 6436AF Anti-Fouling Turbidity Sensor
Copper-based parts on the YSI 6436AF Turbidity Sensor repel aquatic growth on sensors, extending deployment periods.
The YSI 6436AF Turbidity Probe is an anti-fouling, wiped sensor designed to seamlessly integrate - using no external interface hardware - with all YSI sondes that contain an optical port. The YSI 6136 provides accurate, in situ measurement of turbidity in fresh, brackish, and sea water, as well as other applications requiring highly accurate turbidity data.

YSI 6450AF Anti-Fouling Dissolved Oxygen Sensor
The YSI 6450AF anti-fouling DO sensor is a luminescent-based DO sensor that provides accurate long-term measurements in severe fouling and low oxygen environments.

YSI 6425AF Anti-Fouling Chlorophyll Sensor
Predict algae blooms and determine the nutrient loading in water with the YSI 6425AF Chlorophyll Sensor.

YSI 6431AF Anti-Fouling Blue-Green Algae Sensor
The YSI 6431AF blue-green algae sensor monitors algal populations at natural levels in freshwater, providing an early warning for bloom conditions.

YSI 6436AF Anti-Fouling Turbidity Sensor
Copper-based parts on the YSI 6436AF Turbidity Sensor repel aquatic growth on sensors, extending deployment periods.
The YSI 6436AF Turbidity Probe is an anti-fouling, wiped sensor designed to seamlessly integrate - using no external interface hardware - with all YSI sondes that contain an optical port. The YSI 6136 provides accurate, in situ measurement of turbidity in fresh, brackish, and sea water, as well as other applications requiring highly accurate turbidity data.

YSI 6450AF Anti-Fouling Dissolved Oxygen Sensor
The YSI 6450AF anti-fouling DO sensor is a luminescent-based DO sensor that provides accurate long-term measurements in severe fouling and low oxygen environments.

YSI Anti-Fouling C-Spray
Anti-fouling nanopolymer coating that inhibits biofouling attachment on conductivity-temperature probes and other sensors and water quality instruments. 100 mL bottle.

YSI Anti-Fouling Copper Tape
Copper tape for water quality sondes and sensors provides biofouling protection and extends deployments.

YSI EXO1 Anti-Fouling Guard
This copper-alloy sonde guard for the EXO1 protects water quality sensors and provide bio-fouling protection.
The copper construction naturally resists fouling agents in the water and prevents organisms from attaching to the guard.

YSI 650 MDS Multi-Parameter Display System
Log real-time data, calibrate YSI 6-Series sondes, set-up sondes for deployment, and upload water quality data to a PC with the feature-packed YSI 650MDS (Multiparameter Display System). Designed for reliable field use, this display and data logger features a waterproof IP-67, impact-resistant case.

YSI EXO Handheld Display
Introducing the updated EXO Handheld from YSI - In water quality monitoring, instruments must hold up to harsh conditions. Rain or shine, sleet or snow, your equipment needs to keep up with you.