Geotech Mastehead


Water Quality Field Meters

YSI Professional Series Meters

Testing river with YSI Pro


The easiest, most versatile handheld solution for spot sampling in the field or lab. Simply choose the Pro Series model, cable length, and probes that are right for your specific application – from aquaculture to surface water to wastewater and more.

  • Each instrument provides multiple probe
    or cable options.
  • Detachable cables and probes mean less downtime.
  • Backlit keypad and display (Pro Plus) or glow-in-the-dark keypad for low light measurements.
  • IP67 Rated
  • 3-Year Warranty on Instrument
    2-Year Warranty on Cables
    1-Year Warranty on Probes
    6-Month Warranty on Galvanic DO Probes

YSI Professional Plus
Professional Plus

YSI Pro1020, Pro1030, Pro2030
Pro1020, Pro1030, Pro2030

YSI Pro10, Pro20, Pro30
Pro10, Pro20, Pro30

YSI Professional Plus Multiparameter

The flagship of the Professional Series, YSI Professional Plus accommodates any combination of Pro Series probe, cable, and accessory. This compact handheld allows you to instantly change probes and cables. You determine what you want the instrument to measure and display.

  • Choose your own combination of the various parameters:
    Ammonium, Chloride, Conductivity, Dissolved Oxygen (DO), Nitrate, Oxidation Reduction Potential (ORP), pH, Temperature, Salinity, Resistivity, Total Dissolved Solids (TDS)
  • 5,000 data-set memory
  • Interval or single-event logging capability
  • Free, Data Manager desktop software and ProComm II saddle

Call 1-800-833-7958

YSI Professional Series Specifications
YSI Professional Plus User Manual


YSI Pro1020
pH, ORP, ORP/Redox, Polarographic or Galvanic DO sensors, and Temperature.

YSI Pro1030
pH, ORP/Redox, Conductivity, Specific Conductance, Salinity, Total Dissolved Solids (TDS), and Temperature.

YSI Pro2030
DO, Conductivity, Specific Conductance, Salinity, Total Dissolved Solids (TDS), Barometer and Temperature.

YSI Professional Series Specifications
YSI Pro1020 User Manual
YSI Pro1030 User Manual
YSI Pro2030 User Manual

Call 1-800-833-7958


YSI Pro10
pH or ORP/Redox, and Temperature.

YSI Pro20
DO and Temperature.

YSI Pro30
Conductivity, Specific Conductance, Salinity, Total Dissolved Solids (TDS), and Temperature.

YSI Professional Series Specifications
YSI Pro20 User Manual
YSI Pro30 User Manual

Call 1-800-833-7958

YSI Amplified Sensors

YSI ProDSS with 4-Port Bulkhead

probe and cable assembly

Multiparameter Sampling Instrument

The YSI ProDSS (Professional Digital Sampling System) is designed for use in applications such as surface water, groundwater, coastal waters, and aquaculture. The rugged and reliable ProDSS allows for measurement of up to 17 parameters. The ProDSS features user-replaceable digital smart sensors that are automatically recognized by the instrument when connected. A backlit color display, large memory, convenient calibration procedures, rechargeable battery, and powerful PC data management program (KorDSS) make the ProDSS user friendly.

The optional GPS function, wide range of sensors, and varying cable lengths allow for complete customization of the ProDSS. Mil-spec (military spec) connectors and a waterproof (IP-67), rubber over-molded case ensures durability to provide years of sampling even in the harshest field conditions.

  • Single cable design with lengths up to 100 meters
  • 4 port cables feature user-replaceable sensors; universal ports can accept any 4 sensors; optional depth sensor available
  • ODO/CT probe and cable assemblies feature integral (built-in) optical DO and conductivity sensors; rugged ODO sensor cap with 2-year warranty is pre-installed on new assemblies
  • Long-life rechargeable lithium-ion battery to power handheld and sensors
  • Color display and backlit keypad allow for sampling in all lighting conditions
  • Digital smart sensors are automatically recognized by the instrument and store calibration data
  • User-replaceable cables and sensors provide versatility, reduce down time and reduce overall cost of ownership
  • Large memory (> 100,000 data sets) with extensive site list and Data ID tag capabilities
  • KorDSS, a powerful data management software with geo-mapping capability, is included with the instrument
  • USB On-The-Go connector for PC connection, recharging/powering the ProDSS and connecting directly to a USB stick
  • Global Positioning System (GPS) (optional)
  • Cable lengths up to 100 meters available with or without a depth sensor
  • Rugged, waterproof case (IP-67 rated) with rubber over-mold and metal, military-spec (MS) cable connectors as well as rugged titanium sensors
  • Multiple languages in handheld and KorDSS: English, Spanish, Portuguese, French, German, Italian, Japanese, Norwegian, Chinese (simplified and traditional), Korean, and Thai
  • Warranty: 3-year instrument; 2-year cable assembly and sensors; 1-year pH and pH/ORP sensor modules; 6-months ammonium, nitrate and chloride sensor modules.

Call 1-800-833-7958

YSI ProDSS Specifications
YSI ProDSS User Manual
YSI ProDSS Quick Start Guide

YSI Pro20i

YSI Pro20i Dissolved Oxygen/Temperature

Easy to use, rugged and reliable, the YSI Pro20i provides everything you need in a handheld instrument for the measurement of dissolved oxygen (DO). A true field instrument with IP-67 waterproof, rubber over molded case, military spec connectors and 1-meter drop tests ensure durability to provide years of sampling even in the harshest field conditions.

With the Pro20i, accuracy is not compromised for ruggedness. The Pro20i can easily be calibrated for fast, accurate measurements you can trust.

  • Integral (i.e. built-in) Cable: 1, 4, and 10 meter field cables to choose from
  • User-replaceable DO sensors
  • One Touch Cal: Allows for easy DO calibrations within 3 seconds with the press of a button
  • Automatic barometric pressure compensation
  • Quick response times: T-95 response time in 8 seconds with standard membrane (fastest response time on the market)
  • Stores 50 data sets: No need to write down data
  • Large graphic, backlit display and glow in the dark keypad, visible in any lighting condition
  • Display is visible when wearing polarized sunglasses
  • A true field instrument with IP-67, impact-resistant, waterproof case. Waterproof with and without the battery cover.
  • Rubber over molded, slip-proof case provides extra durability
  • Multiple languages: English, Spanish, French, and German
  • Warranty: 3-year instrument, 2-year integral cable, 1-year polarographic sensors, 6-month galvanic sensor

Call 1-800-833-7958

YSI Pro20i Specifications
YSI Pro20i User Manual

YSI ProODO InstrumentYSI ProODO with OBOD Prob anf Lab DockYSI ProOBOD Probe
inserted into BOD bottle
and connected to the YSI ProODO.
All are mounted to the YSI Lab Dock.

Optical Dissolved Oxygen Meter
and ProOBOD Probe

The new ProODO™ provides traditional YSI quality in a handheld dissolved oxygen instrument with luminescent
optical dissolved oxygen (DO) technology. The ProODO utilizes “smart” digital sensor technology which stores calibration data within the sensor. This allows probes to be placed on any ProODO instrument without recalibration.

The YSI ProOBOD probe is used with the YSI ProODO handheld optical dissolved oxygen instrument. The ProOBOD easily connects to the ProODO handheld and makes it convenient to conduct lab BOD’s with a very compact footprint.

  • Expanded DO range of 0-500% with a response time of T90 in 15 seconds
  • Non-consumptive luminescent method eliminates need for stirring
  • Optical technology increases DO accuracy and eliminates probe fouling by common gases such as hydrogen sulfide
  • Easy to read graphic, backlit display and keypad for use in any lighting condition
  • Truly field-worthy, impact resistant, IP67 waterproof case and connectors; rubber over molded, non-slip case, for extra durability and grip
  • User-replaceable cables in lengths of 1 to 100 meters; cable management kit included with 4 meter and longer cables
  • USB connection allows interaction with powerful desktop Data Manager software
  • Stores 5000 data sets (sensor data, date, time, site and user defined information)
  • Multiple languages include English, Spanish, French, Italian, Norwegian, Portuguese and German. Asian language support in the future.
  • 3-year instrument warranty; 2-year cable and
    probe warranty

Call 1-800-833-7958

YSI ProODO Specifications
YSI ProODO User Manual
YSI ProOBOD User Manual



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