New Products

EXO1s Multiparameter Sonde

EXO1s Multiparameter Water Quality Batteryless Sonde (4 sensor ports)

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ProSwap Logger

Single-Port Monitoring Sonde

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EXO NitraLED UV Nitrate Sensor

EXO NitraLED UV Nitrate Sensor for Freshwater Environments

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SonTek RS5

Acoustic Doppler Current Profiling System

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ProQuatro Multiparameter Meter

Portable Sampling Handheld Meter for DO, Conductivity, Salinity, TDS, pH, ORP, Ammonium, Nitrate, Chloride, Temperature and more


One Team on a Mission

Spanning nearly 75 years, YSI, a Xylem brand has a customer-focused legacy of developing innovative, environmentally essential technology. Our customers are more than people who use our instruments - they are climate first responders, environmental stewards, and researchers who are passionate about our world along with scientific integrity.

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Ammonia-Based Aeration Control | Improvements Through Sensor Placement


A crucial aspect of implementing an ammonia-based aeration control system is ammonium sensor placement. Should the control sensor be near the influent of the activated sludge basins, at the effluent of the activated sludge basins, or...

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Featured Products

ProDSS Multiparameter Digital Water Quality Meter

The Ultimate Sampling Handheld. Portable Digital Meter for DO, Conductivity, Salinity, TDS, pH/ORP, Turbidity, Algae, Temperature and more

$1,965.00 - $2,585.00

EXO2 Multiparameter Sonde

Multiparameter Water Quality Sonde for Unattended Monitoring (7 sensor ports, including a central wiper port)

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IQ SensorNet 2020 3G Controller

Modular water quality monitoring system for a complete sensor network that measures up to 20 parameters

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Pontoon Vertical Profiling System

Ideal for Ponds, Lakes, Reservoirs, and Certain Coastal Applications

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ProSolo Digital Water Quality Meter

Portable Optical Dissolved Oxygen, Conductivity, Salinity, and Temperature Digital Handheld Meter


2900M Online Monitor & Control System

Two Chemistry Online Monitor & Control System

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MultiLab 4010-3W

Three channel benchtop multiparameter instrument with wireless capability


HYCAT Autonomous Surface Vehicle

Autonomous Surface Vehicle

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Amazon Bubbler

Self-contained Continuous Flow Bubbler with Fully Integrated Pressure Sensor

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IQ SensorNet Alyza Analyzer PO4

IQ SensorNet Orthophosphate Analyzer

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Determine The HAB Monitoring Solution For You

The intuitive YSI HAB (Harmful Algal Bloom) monitoring system selector will provide you with a recommendation for the HAB monitoring solution that best fits your requirements! Your answers to the selector questions will help you think through your options, and will help YSI to get you a solution as fast as possible. You might even be able to buy your solution online TODAY!

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Finding the right handheld water quality meter should be easy. Just take our short quiz and the intuitive product selector will provide you with an immediate recommendation based on your needs! From the single-parameter, analog Pro10 to the multiparameter, all-digital ProDSS, we've got you covered.

Choose the Right Handheld

What is the Best Titrator for You?

YSI offers a full range of titration solutions to accommodate your titration requirements. Manual or Automated? We can help! Our titrators, and compatible accessories, efficiently determine concentration levels and quickly detect equivalency points accurately.

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What is The Floating Platform for Your Monitoring Needs?

An Integrated System from YSI can be built for almost any water monitoring application. Reveal water quality in the entire water column with a vertical profiler, configure your own unique data buoy or TurnKey system for real-time data collection.

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Get back to basics with Xylem's Titration Handbook:  an  all-encompassing guide to help any laboratory navigate one of the oldest quantitative methods in chemical analysis.

Download the Handbook


Our experts dive into the evolution of sensor technology and how they work. In this series, we dive into the following parameters in great detail; algae, turbidity, conductivity, pH & ORP, and dissolved oxygen.

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