How do I calibrate the Milwaukee MA887 Digital Refractometer?

The refractometer needs to be calibrated before each use. You can take several readings after a single calibration but as soon as you turn OFF the refractometer for storage, the calibration will need to be performed again.

  1. Press the ON/OFF button, when you see four dashes, the meter is ready.
  2. Using the plastic pipette, fill the sample well with the included distilled water.
  3. Verify the prism in the well is completely covered with water.
  4. Press the ZERO button.
  5. As long as no error messages are displayed, the refractometer is now calibrated and ready for use. 

How do I use the Milwaukee MA887 Digital Refractometer?

After calibration, use a soft cloth to remove the distilled water from the prism well. Be sure it is thoroughly dry before taking a measurement. 

  1. Use the plastic pipette to draw water from your aquarium.
  2. Fill the prism well with aquarium water being sure the glass prism is completely covered.
  3. Press the READ button.
  4. Record salinty results.
  5. Remove saltwater from the well with a soft cloth.
  6. Use a small amount of distilled water to rinse the prism well and then dry with a soft cloth.

How do you read the results?

The Milwaukee MA887 can provide three different types of salinity measurements. In the aquarium hobby, we typically use S.G. or PPT.

  • PSU - Practical Salinity Units
  • PPT - Parts Per Thousand
  • S.G. - Specific Gravity

You can switch between the different units of measure by pressing the RANGE button. The larger numbers on top are the salinity results and the smaller number in the bottom right is the water temperature.

How do you switch between C° and F°?

  1. Turn the Milwaukee MA887 OFF.
  2. Press and hold the ON/OFF button for 8 seconds.
  3. The screen will display 887 after 8 seconds.
  4. Keep holding the ON/OFF button and simultaneously press the ZERO button to toggle between C° and F°.

Can I use distilled water for calibration?

Yes, the Milwaukee MA887 can be calibrated using either distilled water or 0 TDS RO/DI water.