Milwaukee Dissolved Oxygen Meter 0.0 to 19.9 Mg/l (ppm)

The Dissolved Oxygen Meter Milwaukee MW600 is one of Milwaukee's most popular meters with its reliable and fast operation as well as its accuracy.

Great for field biologists and educators, fish farmers and koi pond owners

The Milwaukee MW600 PRO DO Meter has been widely recognized in water quality studies for providing laboratory-level dissolved oxygen measurements in the field. Independent testing and peer-reviewed articles highlight its precision and ease of use, making it a trusted instrument in aquaculture research, environmental monitoring, and educational programs. Customers consistently praise its reliability, quick response, and user-friendly calibration, and it is commonly used for monitoring fish ponds, aquariums, wetlands, and other aquatic systems.

Professional Accuracy Without the High Cost

The Milwaukee PRO DO Meter is preferred by people looking for lab-level accuracy without the cost.

DESIGN FEATURES

• Fast, easy-to-read results with large digital LCD readout
• Repeatable, accuracy to ±1.5% FS
• Lightweight and portable
• Simple 2 point open air calibration (see video below)
• Uses MA840 reinforced polarographic probe with an oxygen-permeable polytetrafluroethylene (PTFE) membrane sensor
• 5 o-rings, membranes and one protective cap included
• 10 feet probe cable for extra flexibility when testing
• 70 hours of battery life with continuous use (battery included) with low battery warning

CARE AND USE

“OPEN AIR” CALIBRATION PROCEDURE

1. Remove the membrane
   Take the membrane off the end of the probe and dry the diode off.
2. Zero out the display
   Connect the probe to the base unit and turn the unit on. Your display should read 0.0. If it does not, adjust the “0” screw on the front of the unit using the screwdriver provided so the display reads 0.0.
3. Fill the membrane
   Place the “O” ring inside the membrane on the shoulder at the base of the threads. Fill the membrane just short of the “O” ring with MA9071 electrolyte solution, ensuring there are no air bubbles inside the membrane.
4. Attach the membrane
   Screw the membrane onto the probe securely.
5. Let stabilize
   Turn the meter on and hang the probe off the edge of a table pointing down. Allow the display to stabilize (5–15 minutes).
6. Adjust
   Press and hold the “Cal” button on the meter and adjust the front Cal position to “100%” using the screwdriver so the display reads 100. Your meter is now calibrated.

EXTRA TIPS

• Watch for wrinkles or stretch marks on the membrane. Replace if present.
• Always use fresh MA9071 electrolyte solution for reliable calibration.

To enhance your aquatic and water quality monitoring capabilities beyond the Dissolved Oxygen Meter — designed for precise measurement of oxygen concentration in water and other liquids — consider additional instruments that support comprehensive water analysis workflows. The Benchtop Dissolved Oxygen Meter offers advanced laboratory-grade performance with higher accuracy and multi-parameter logging for research and QA/QC applications.

For portable field testing, the Portable Water Quality Meter combines dissolved oxygen measurement with pH, conductivity, and temperature monitoring, providing a versatile solution for on-site water analysis. Additionally, the 2‑Channel Temperature and Humidity Logger allows concurrent environmental monitoring, which is critical for understanding conditions that may affect oxygen solubility in aquatic environments.

Q&A

What is the accuracy of the Milwaukee MW600?

The MW600 provides repeatable results with an accuracy of ±1.5% FS, suitable for field and laboratory applications.

How often should I replace the membrane?

Replace the membrane whenever you notice wrinkles, stretch marks, or any visible damage. Regular replacement ensures accurate readings.

Can I use this meter in both freshwater and saltwater?

Yes, the MW600 can be calibrated and used in both freshwater and saltwater environments.

How long does the battery last?

The meter has approximately 70 hours of continuous battery life, with a low battery warning to ensure uninterrupted use.

Is the probe cable long enough for deep ponds?

The MW600 comes with a 10-foot probe cable, providing flexibility for most small to medium-sized ponds or tanks.