YSI Pro20 Dissolved Oxygen Meter

The YSI Pro20 dissolved oxygen meter (sensors sold separately) is a rugged, user-friendly instrument used for dissolved oxygen measurement in the lab or field.


  • One Touch Cal feature allows % mode calibration with the press of a button
  • IP67 waterproof, Military Spec connectors, rubber over mold, 1-meter drop test
  • 95% response time in approximately 8 seconds with standard membrane
List Price $738.00
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The YSI Pro20 is a handheld dissolved oxygen and temperature meter ideal for use in the lab or field. Utilizing YSI's durable MS (Military Spec) cable connector, the instrument can accept rugged field sensors or a self-stirring lab BOD sensor. To meet the needs of various applications, cables are bought separately in lengths from 1 to 100 meters. The included cable management kit even makes the use of long cables easy and convenient.

One Touch Cal
The Pro20 is YSI's first dissolved oxygen instrument to offer a convenient "One Touch Cal" feature for air calibrations. This unique feature, along with others like user-replaceable sensors, simplifies operation and saves time and money. The YSI Pro20 is completely waterproof, withstands 1-meter submersion and has an industry-leading 2-year cable warranty making it field-worthy.

Additional Features

  • 3-year instrument; 2-year cable; 1-year Polarographic/6-month Galvanic sensor warranty
  • Field-replaceable electrodes (choose between Polarographic or Galvanic)
  • One-touch cal allows DO calibration with the press of a button
  • Stores 50 data sets to ensure data integrity
  • Graphic, backlit display
  • Standard 1- 4- 10- 20- 30- and 100-m weighted cable lengths (special order up to 100-meter
  • cables in 10-meter increments)
  • IP-67, impact-resistant, waterproof case
  • Easy-to-use, screw-on cap DO membranes
  • English, Spanish, German and French languages
  • Glow in the dark keypad
  • Quick response times

*Pro20 purchases include the instrument, manual, batteries, USB cable, and USB flash drive. Cables and probes are ordered separately.

  • Barometer: Built-in barometer
  • Cable Lengths: 1- 4- 10- 20- 30- up to 100m lengths (3.28, 13.1, 32.8, 65.6 ft.)
  • Certifications: RoHS, CE, WEEE, IP-67, 1-meter drop test
  • Connector: MS (military spec) waterproof with bayonet lock
  • Data Memory: 50 data sets
  • Dimensions: 8.3 cm width x 21.6 cm length x 5.6 cm depth (3.25 in x 8.5 in x 2.21 in)
  • Languages: English, Spanish, German, French
  • Power: 2 alkaline C-cells providing approximately 400 hours of battery life depending on backlight usage; low battery indicator
  • Salinity Input Range: 0-70 ppt
  • Warranty: 3-year instrument; 2-year cable; 1-year Polarographic sensors; 6-months Galvanic sensors
  • Waterproof: IP-67 (even with the battery cover off)
  • Weight with Batteries: 475 grams (1.05 lbs)
  • (1) YSI Pro20 display
  • (1) Operations manual
  • (2) C-cell batteries
Questions & Answers
Can the Pro20 interface with a PC via a Pro Plus communications saddle?
No. Connecting the Pro20 to a communications saddle may cause the device to behave erratically.
What cables are compatible with the Pro20 dissolved oxygen sensor?
The YSI Pro20 is compatible with the Pro20 cable assemblies and the ProBOD probe. The field rugged cables incorporate a temperature sensor are available in lengths of 1, 4, 10, 20, 30, and 100 meters. The cables are compatible with both the 2002 galvanic and 2003 polarographic sensors. The ProBOD probe has 1 meter cable and comes with a built in dissolved oxygen and temperature sensor.
Does this meter store my data measurements?
The Pro20 dissolved oxygen meter can store up to 50 data sets on its internal memory for later viewing.
Which electrochemical DO sensor doesn't require warm-up after powering on the meter?
The YSI Galvanic dissolved oxygen sensor requires less warm up time than the Polarographic sensor due to the fact that the probe is always considered active (charged) while the meter is powered off.
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YSI Pro20 Dissolved Oxygen Meter
Pro20 dissolved oxygen meter (cable/sensor sold separately)
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YSI Pro20 Dissolved Oxygen Meter
Pro20 Gal DO 4m Field Kit: Includes Pro20, Pro20 4m cable, 2002 galvanic DO sensor & 6262 case
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YSI Pro20 Dissolved Oxygen Meter
Pro20 Pol DO 4m Field Kit: Includes Pro20, Pro20 4m cable, 2003 polarographic DO sensor & 6262 case
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YSI Pro20 Dissolved Oxygen Meter
Pro20 Gal DO 10m Field Kit: Includes Pro20, Pro20 10m cable, 2002 galvanic DO sensor & 6262 case
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YSI Pro20 Dissolved Oxygen Meter
Pro20 Pol DO 10m Field Kit: Includes Pro20, Pro20 10m cable, 2003 polarographic DO sensor & 6262 case
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YSI Pro20 Dissolved Oxygen Meter
Pro20 BOD Lab Kit: Includes Pro20, ProBOD, lab dock & 5518 power supply
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YSI Pro20 Dissolved Oxygen Meter
Pro20 Pol DO 4m Lab/Field Kit: Includes Pro20, ProBOD, Pro20 4m cable, 2003 polarographic DO sensor, lab dock, 5518 power supply & 6262 case
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