The YSI ProQuatro Portable Multiparameter Water Quality Meter is a rugged, field-ready water quality monitoring solution engineered for environmental professionals, water resource managers, and research scientists. Designed for comprehensive water quality analysis in groundwater, surface water, coastal, agricultural, and environmental compliance applications, the ProQuatro combines portability, durability, and expansive measurement flexibility into a single handheld platform.

This versatile meter supports an array of sensor combinations, allowing simultaneous measurement of dissolved oxygen (DO), pH, conductivity, salinity, specific conductance, TDS, ORP, temperature, and ion-selective parameters such as ammonium, nitrate, and chloride, giving precise insights for environmental baseline studies, regulatory compliance sampling, and routine field monitoring.

Perfect for field use with its impact-resistant, waterproof (IP-67) handheld design, intuitive graphic display, and robust data logging, the ProQuatro is ideal for agencies, labs, consultants, and industrial water quality programs.

Choose your Meter and Cable below. 

Need a replacement probe or parameter-specific sensor?
Explore the ProQuatro Sensors page to find compatible DO, pH, conductivity, ORP, and ISE sensors.

Need a Flow Cell or other accessories?
Explore the ProQuatro Accessories page 

ProQuatro Features:

• Multiparameter Field Monitoring – Simultaneously measures dissolved oxygen, pH, conductivity, salinity, TDS, ORP, temperature, and select ISE parameters.
• Rugged, Waterproof Design (IP-67) – Built for harsh field conditions; impact-resistant, submersible, and floatable.
• Flexible Sensor & Cable Options – Interchangeable sensors and multiple cable lengths support diverse sampling environments.
• Long Battery Life – Up to 80 hours of continuous field operation with standard batteries.
  
• Integrated Data Logging – Stores up to 5,000 datasets with easy USB data transfer for reporting and compliance.
• Low-Flow Sampling Compatibility – Supports flow cells for groundwater and low-flow well sampling applications.

ProQuatro Applications: 

• Groundwater & Well Sampling - Ideal for aquifer monitoring, site assessments, and low-flow sampling programs.
• Surface Water Monitoring – Rivers, lakes, streams, and reservoirs for baseline studies and environmental compliance.
• Drinking Water & Wastewater Screening – Field screening to support regulatory and EPA-aligned monitoring programs.
• Agricultural & Irrigation Water Quality – Monitor salinity, nutrients, and pH to support crop and soil management.
• Coastal, Marine & Aquaculture Monitoring – Track dissolved oxygen and salinity in estuarine and aquatic environments.
• Environmental Research & Field Studies – Portable data collection for academic, consulting, and government research.

Specifications

User Manual