Milwaukee MW190 Portable DO Meter for Environmental and Laboratory Water Analysis

Milwaukee Oxygen Meter for Measuring Dissolved Oxygen — Dissolved oxygen checks in water and process samples

This Meter is most useful for aquaculture, environmental, and wastewater teams who need a portable instrument for field or lab verification of oxygen levels for treatment efficiency, aquatic health, or process control.

The Milwaukee MW190 MAX DO Bench Meter has been referenced in laboratory testing studies for its consistent dissolved oxygen measurements in water quality analysis. Reviews from educators, fishery managers, and laboratory technicians highlight its dependable performance and user-friendly interface. Common applications include monitoring oxygen in aquaculture, environmental testing, educational labs, and water treatment facilities, where users appreciate both its speed and accuracy.

The Milwaukee MW190 MAX DO Bench Meter is preferred by people looking for lab-level accuracy without the high cost. The Milwaukee DO Meter is popular with everyone from field biologists, educators, fish farmers, koi pond owners, educational institutions, water treatment plants, and laboratories.

DESIGN FEATURES

• Fast, easy-to-read results with large digital LCD readout.
• Repeatable, accuracy to ±1.5% FS.
• Lightweight with a small benchtop footprint.
• Single offset or dual point slope with open air 100% saturation calibration.
• Altitude and salinity compensation.
• Automatic temperature compensation.
• Uses MA845 (included) reinforced polarographic probe with an oxygen-permeable polytetrafluoroethylene (PTFE) membrane sensor.
• Includes 5 O-rings, membranes, and one protective cap.
• 2-meter probe cable for extra flexibility during testing.
• Logging capability for up to 50 samples.
• 12 VDC power supply.
• Easy RS232/USB opto-isolated connection.
• Complete with DO probe, initial calibration solutions, and cables.

CARE AND USE

PROBE PREPARATION AND CALIBRATION PROCEDURE

D.O. Probes are shipped dry. To hydrate the probe and prepare it for use, connect it to the meter and follow these steps:

1. Remove the red and black shipping caps.
2. Wet the sensor by soaking the bottom 2.5 cm of the probe in the electrolyte (MA9071) for 5 minutes.
3. Rinse the membrane with electrolyte solution while gently shaking it. Refill with clean electrolyte solution.
4. Tap the sides of the membrane lightly with a fingertip to remove trapped air bubbles. Avoid tapping the membrane directly on the bottom.
5. Place the O-ring properly inside the membrane cap.
6. With the sensor facing down, screw the cap clockwise. Some electrolyte overflow may occur.
7. Turn the unit on using the on/off key.
8. All LCD tags display and a beep sounds while the instrument runs a self-test.
9. The "COND" message displays for ~45 seconds during auto-conditioning (automatic polarization).
10. Once "COND" disappears, the probe is polarized and ready for calibration.

Calibration Offset Procedure

1. Remove the clear protective cap.
2. Submerge the probe in MA9070 zero oxygen solution and stir for 2–3 minutes.
3. Press CAL. The "WAIT" tag blinks on the LCD until the reading stabilizes.
4. When stable, "READY" & "ACCEPT" tags blink. Press ACCEPT to confirm 0.0% D.O. calibration.

Note: When not in use, cover the membrane with the supplied clear plastic cap.

Extra Tips

• Check membranes for wrinkles or stretch marks and replace if needed.
• Always use fresh electrolyte solution (MA9071) for accurate readings.

To broaden your water quality analysis capabilities beyond the Dissolved Oxygen Meter with Calibration — a bench‑meter designed for precise dissolved oxygen measurement with automatic calibration and temperature compensation ([turn0search0](#)) — consider integrating additional professional water testing instruments that enhance multi‑parameter insights and field versatility. The Multiparameter Water Quality Meter delivers combined measurement of pH, conductivity, dissolved oxygen, turbidity and more with quick calibration functions for each parameter ([turn0search2](#)). For portable field use where robust, rugged monitoring across salinity, temperature, and dissolved oxygen is critical, the Multiparameter Water Quality Meter (Hi9829C4T) offers a customizable, IP67‑rated platform with automatic compensation and extensive logging capability. Additionally, the Benchtop Dissolved Oxygen Meter provides advanced laboratory‑grade DO measurement with calibration reminders and data logging.

Technical Q&A

What is the measurement range?

The meter measures dissolved oxygen from 0.00 to 45.00 mg/L (ppm), making it suitable for most laboratory and field applications.

Can this meter be used in both freshwater and saltwater?

Yes, it has built-in salinity compensation, allowing accurate measurements in freshwater, saltwater, and brackish environments.

How often should the probe be calibrated?

Calibration is recommended before each use or whenever accuracy is critical, typically after auto-conditioning of the probe.

Is the probe replaceable?

Yes, the MA845 probe is included and replaceable. Extra membranes and O-rings are also provided to maintain long-term performance.

Does the meter support data logging?

Yes, it can log up to 50 samples, which can be exported via RS232 or USB connection.

What makes this kind of instrument practical for daily use?

Portable operation, straightforward calibration routines, and application-specific sensors or scales help teams get faster and more repeatable results where the work is actually happening.

Who benefits most from this product?

Aquaculture, environmental, and wastewater teams benefit most when they need quick, defensible readings for process adjustments, troubleshooting, or documented quality checks.

Because it combines Fast, easy-to-read results with large digital LCD readout, Repeatable, accuracy to ±1.5% FS, Lightweight and has a small benchtop footprint, this product is a strong fit for dissolved oxygen checks in water and process samples in real operating conditions.