550A Dissolved Oxygen Instrument

The 550A dissolved oxygen instrument has been discontinued. YSI will continue to support existing 550A's through 2020. We recommend the Pro20i as a direct replacement. The Pro20 and ProSolo handheld instruments are also suitable replacements.

• Overview

  Features:

  • Field-replaceable DO electrode modules
  • Screw-on cap membranes
  • IP-67 case
  • Over 2000 hours battery life
  • Calibrate in either mg/L or % saturation

  Be the envy of your co-workers by winning a ProSolo ODO/T system! Enter to win a ProSolo optical DO system.

  Please visit our extensive dissolved oxygen resource page to learn about all things DO and BOD related.

  You can also download The Dissolved Oxygen Handbook - the definitive guide on all things DO.

• Specifications

  Certification	High-impact resistance, IP-67, CE
  Graphic Display	Graphic
  Measurement Range	Dissolved Oxygen-0 to 500% air saturation/0 to 50 mg/L, Temperature--5 to 45°C
  Multiparameter	Yes
  Parameters Measured	Dissolved Oxygen, Temperature
  Power	Low battery indicator on display, Over 2000 hours at 25°C, 4 alkaline C-cells
  Sampling	Yes
  Unit of Measure	Dissolved Oxygen-% air saturation, Temperature-°C, mg/L
  User Calibratable	Yes
  User Replaceable	Yes
  Warranty	3-year instrument; 1-year DO module
  Waterproof	floats, IP-67 (even with the battery cover off)

• Accessories

  

  Cap Membrane Kit 1.25 Mil PE

  Cap Membrane Kit 1.25 Mil PE (6 each), Polarographic, includes electrolyte (yellow cap)

  

  DO Replaceable Probe

  DO Replaceable Probe

• Manuals
  • YSI 550A Operations Manual
• Repair Part Schematics
  • YSI Model 550A Exploded View