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Milwaukee Seawater Digital Salinity Aquarium Refractometer Specific Gravity Milwaukee Instruments Seawater (Salinity) Refractometer

The MA887 Milwaukee Instruments Seawater (Salinity) Refractometer is an optical instrument that employs the measurement of the refractive index to determine the salinity of natural and artificial seawater, ocean water or brackish intermediates. The digital refractometer eliminates the uncertainty associated with mechanical refractometers.

To use, after calibrating, you just put a sample of your water into the prism tray of the Milwaukee Seawater Refractometer. Within seconds the refractive index and temperature are measured and converted into one of three popular measurement units; Practical Salinity Units, Salinity in parts per thousand or Specific Gravity. The measurement is displayed digitally on the LCD screen.


  • Automatic Temperature Compensation
  • Battery operation with Low Power indicator
  • Automatically turns off after 3 minutes of non-use
  • Product Manual (pdf format in new window)

List Price: $145.00
Our Price (price includes free shipping!) $126.49
You save $18.51!
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JBJ C-Scope Refractometer with ATC JBJ C-Scope Refractometer w/ ATC

The JBJ C-Scope Refractometer w/ ATC is designed for testing the concentrations of saltwater by providing a direct reading of the speciific gravity and salinity in ppt. It provides a reliable refractive index and salinity readings of total dissolved solids of aqueous solutions. The refractive index is the ratio of the the speed of light in a vacuum to the speed of light in the medium (saltwater) being measured. Light is slowed by passing through saltwater, so the index of the refraction is an indication of this speed change.

You simply add a few drops of your saltwater water over the prism and focus the eyepiece under direct lighting until you see a line that divides the scale from blue and white. This line indicates the specific gravity and the salinity.


  • Magnified Dual Scale. This simple integrated feature magnifies the scale over 2x compared to traditional refractometers for easy viewing.
  • ATC - Automatic Temperature Compensation. Since water temperature effects salt readings, all C-scope refractometers are equipped with ATC to give the correct reading even if your water temperature isnt.
  • Quick Calibration. The ability to calibrate the refractometer allows you to cross reference your readings without ever have to second guess yourself.
  • Deep Color Contrast. The C-Scope was designed to provide a clear and sharp dual scale. This is accomplished with a deep color contrast between the blue and white to quickly distinguish your measurement.

    Our Price: $79.99
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    Aqua Medic Refractometer Aqua Medic Refractometer

    The Aqua Medic Refractometer is a precision optical instrument used to determine the salt concentration in saltwater aquaria.

    Our Price: $77.99
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    Red Sea Seawater Refractometer Red Sea Seawater Refractometer

    Red Seas Seawater Refractometer offers exceptional accuracy, for measuring the absolute salinity of seawater at a temperature of 77F. Most refractometers used within the aquarium hobby are not specifically designed for reef aquariums and use an algorithm for the measurement of brine (NaCl rather than seawater) and at a temperature of 59F rather than 77F. Thus, a measurement deviation of up to 1.5 ppt is possible, which can have a significant adverse effect on coral growth and coloration.

    • User Manual
    • Directly reads the absolute salinity of seawater at 77 F ( No need for seawater or temperature compensation factors)
    • Specifically designed for the ionic content of seawater (NSW) for more accurate salinity measurement (industry standard refractometers are calibrated for salt brine ).
    • Calibrated for seawater (NSW) at 77 F, the normal temperature range for reef aquariums (most standard refractometers are calibrated at 59F).
    • Easier to read, higher resolution display, focussed to the relevant range for reef aquariums of up to 40 ppt
    • Includes Integrated Automatic Temperature Compensation (ATC) for accurate measurement at standard ambient temperature.

      Our Price: $59.99
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      Pinpoint Salinity Calibration Fluid American Marine Pinpoint Salinity Calibration Fluid

      53.0 mS standardized fluid for calibrating refractometers and the American Marine PinPoint Salinity Monitor.

      Our Price: $9.79
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      Two Little Fishies AccuraSea 250 ml Two Little Fishies AccuraSea, 250 ml

      With Two Little Fishies AccuraSea you can measure your salinity precisely. AccuraSea seawater reference solution is the only calibration solution of its kind made from real seawater. Its pure natural sea water micron filtered and UV sterilized then adjusted with reverse osmosis water to the standard S = 35 or conductivity of 53 mS/cm at 25C (77F). Use it to accurately calibrate seawater refractometers and check the accuracy of swing-arm hydrometers. You may also want to use it as a reference for test kits used to measure the concentrations of various seawater components, since it is natural seawater with the correct and well-known concentrations of all dissolved salts. 250 ml bottles.

      Our Price (price includes free shipping!) $7.99
      In Stock