• DO, pH, Conductivity, ORP, Ammonium, Nitrate, Chloride, Salinity, Total Dissolved Solids, Barometric Pressure
  • Ranges and accuracy dependent upon probes and cables
  • 2,000 data-set memory with GLP event logging
  • Interval or single event logging capability
  • Rubber, over-molded IP-67 water proof case
  • 3-year instrument warranty
  • User- upgradeable software via USB
  • Backlit display and keypad
  • Graphic display with detailed Help


The YSI Professional Plus handheld multiparameter meter is the toughest, smartest and most versatile water quality meter available. The Pro Plus is a true multiparameter meter capable of fast and accurate measurements of a variety of combinations of dissolved oxygen, conductivity, specific conductance, salinity, resistivity, total dissolved solids (TDS), pH, ORP, pH/ORP combination, ammonium (ammonia), nitrate, chloride and temperature.

The YSI Pro Plus provides numerous benefits from the following advanced features: 2,000 data-set memory, password protection, backlit display and keypad, graphic display with detailed Help functionality, re-cal prompts, user defined fields, detailed GLP, auto stable, Hold All Readings function, Data Manager software for the desktop, USB connection, auto-buffer recognition, and flexible folders and site lists for logging data.

The Pro Plus also meets the demands of true field work. The YSI Professional Plus Multiparameter Meter is rated to IP-67 standards even without the battery cover on. Other tough features on the YSI Professional Plus Multiparameter Meter include Mil-spec connectors and the rubber over-molded case. The YSI Pro Plus is protected by a 3-year warranty and vigorous in-house testing that includes 1-meter drop tests from all angles to ensure expected field-durability.

The YSI Professional Plus handheld multiparameter meter includes the meter, manual, batteries, communications saddle, USB cable and Data Manager software. Cable and probes are not included and must be purchased separately.

This meter requires regular calibration to perform at its optimal level. We strongly suggest purchasing calibration standards and solutions which are available as accessories.

Choose from 22 Pro Plus kits. Kits include everything from lab to field (or both), single to multiparameter, or U.S. to International versions and more. EPA approved for drinking water and wastewater compliance reporting.







Please consider these optional accessories.


This product can be used in the following applications:

Here's how some of our customers use this product...

Measuring Multiple Parameters at Varying Depths in the Field

The Background: The customer, an engineering firm doing site analysis prior to a large infrastructure project, needs to measure multiple water quality parameters at varying depths.

The Problem: The customer had used other multi-parameter instruments in the past but quickly discovered their limitations. Though certain parameters, such as conductivity and dissolved oxygen, can vary greatly with water depth, measuring at multiple depths is tricky. With other multi-parameter water quality meters, each electrode (typically four) has its own cable, making it likely that they get tangled, leading to frustration and taking much longer than necessary to conduct the tests.

The Solution: The YSI Professional Plus Multi-parameter Meter is optimized for field use and utilizes a single, rugged, watertight, cable with Mil-spec connectors. For cables 4m or longer, a cable management tool is provided. This, coupled with the IP67 case, makes the YSI Professional Plus the best instrument for multi-parameter water quality measurements in the field.