Make routine salinity measurement in marine aquariums extremely fast and easy. Milwaukee Instruments Seawater Digital Refractometer is a precision digital refractometer that displays test results in approximately 1.5 seconds! Smartly priced unit is great for all saltwater aquarium hobbyists, beginner or experienced, that require precision marine aquarium testing. For use with all marine (saltwater) aquariums and brackish setups.
Milwaukee Instruments Seawater Digital Refractometer measures and displays temperature compensated results in Practical Salinity Units (PSU), Salinity in parts per thousand (ppt), or Specific Gravity (S.G. (20/20)). Professional optical instrument delivers the highest accuracy possible for the measurement of these three seawater specific scales for a much more precise evaluation of saltwater aquariums. All conversion algorithms based upon respected scientific publications using the physical properties of seawater (not sodium chloride).
Milwaukee Instruments Seawater Digital Refractometer with large dual level LCD screen displays test results and temperature (in °C or °F) along with helpful message codes. Portable, 9V battery-operated unit features a low power indicator and turns off automatically after three minutes of nonuse. Simple calibration requires only distilled or deionized water.
Milwaukee Instruments Seawater Digital Refractometer includes: MA887 Digital Refractometer, 9V Alkaline Battery, and 2 Pipettes.
1.000-1.114 S.G. (20/20)
0-80°C / 32-176°F
0.001 S.G. (20/20)
0.1°C / 0.1°F
±0.002 S.G. (20/20)
±0.3°C / ±0.5°F
||Approximately 1.5 seconds
|Mininmu Sample Volume
||100µL (cover prism totally)
||SS ring and flint glass prism
||Automatic between 10 and 40°C (50 to 104°F)
||1 x 9V (included)
|Auto Shut Off
||After 3 minutes of non-use
||7-1/2" x 4-1/4"x 2-1/2" high
Shop all Aquarium Controllers and Monitors.
- Handle instrument carefully. Do not drop.
- Do not immerse instrument under water.
- Do not spray water to any part of instrument except the Sample Well located over the prism.
- The instrument is intended to measure seawater solutions. Do not expose instrument or prism to solvents that will damage it. This includes most organic solvents and extremely hot or cold solutions.
- Particulate matter in a sample may scratch the prism. Absorb sample with a soft tissue and rinse Sample Well with deionized or distilled water between samples.
- Use plastic pipettes to transfer all solutions. Do not use metallic tools such as needles, spoons or tweezers as these will scratch the prism.
- Cover Sample Well with hand if measuring in direct sun.
Calibration should be performed daily, before measurements are made, when the battery has been replaced, between a long series of measurements, or if environmental changes have occurred since the last calibration.
- Press the ON/OFF key, then release. Two instrument test screens will be displayed briefly; all LCD segments followed by the percentage of remaining battery life. The meter will then briefly display an indication of the set measurement unit. When the LCD displays dashes, then the instrument is ready to use.
- Using a plastic pipette, fill the Sample Well with distilled or deionized water. Make sure the prism is completely covered. NOTE: If the ZERO sample is subject to intense light such as sunlight or another strong source, cover the Sample Well with your hand or other shade during the calibration.
- Press the ZERO key. If no error messages appear, your unit is calibrated. NOTE: The 0 screen will remain until a sample is measured or the instrument is turned off.
- Gently absorb the ZERO Water Standard with a soft tissue. Use care not to scratch the prism surface. Dry the surface completely. The instrument is ready for sample measurement. NOTE: If the instrument is turned off, the calibration will not be lost.
Verify the instrument has been calibrated before taking measurements.
- Wipe off the prism surface located at the bottom of the Sample Well. Make sure the prism and Sample Well are completely dry.
- Using a plastic pipette, drip sample onto the prism surface. Fill the Sample Well completely. Note: if the temperature of the sample differs significantly from the temperature of the instrument, wait approximately one minute to allow thermal equilibration.
- Press the READ key. The results are displayed in units selected by the user. NOTE: The last measurement value will be displayed until the next sample is measured or the instrument is turned off. Temperature will be continuously be updated. NOTE: The "ATC" tag blinks and automatic temperature compensation is disabled if the temperature exceeds 0-40°C / 32-104°F range.
- Remove the sample from the Sample Well by absorbing it with a soft tissue.
- Using a plastic pipette, rinse prism and Sample Well with distilled or deionized water. Wipe dry. The instrument is ready for the next sample.
Changing Measurement Unit
Press the RANGE key to select measurement units. The instrument toggles between the three measurement scales each time the key is pressed and the primary display indicates "PSU", "PPt", and "S.G." When the instrument displays the screen with four dashes, the instrument is ready for measurement. A number on the display indicates the selected unit: "1" denotes PSU, "2" denotes ppt and "3" denotes Specific Gravity.
Changing Temperature Unit
To change the temperature measurement units from Celsius to Fahrenheit (or vise versa); follow this procedure:
- Press and hold the ON/OFF key continuously for approximately eight seconds. The LCD will display the "all segment" screen followed by a screen with the model number on the primary display and the version number on the secondary display. Continue pressing the ON/OFF key.
- While continuing to hold the ON/OFF key, press the ZERO key. The temperature unit will change from °C to °F or vise versa.
Making a Standard Sodium Chloride Solution
Sodium Chloride solutions can be used to check the accuracy of the meter. The table below lists two sodium chloride solutions and their expected ppt Seawater value.
To make a Standard NaCl Solutions (g/100g); follow the procedure below:
- Place container (such as a glass vial or dropper bottle that has a cover) on an analytical balance.
- Tare the balance.
- To make and X NaCl solution, weigh out X grams of high-purity dried Sodium Chloride directly into the container.
- Add distilled or deionized water to the container so the total weight of the solution is 100 g.
||g of NaCl
||g of Water
||Expected ppt Seawater Value
To replace the instrument's battery, follow these steps:
- Turn the instrument OFF by pressing the ON/OFF key.
- Turn instrument upside down and remove the battery cover by turning it counterclockwise.
- Extract the battery.
- Replace with fresh 9V battery making certain to observe polarity.
- Insert the battery cover and fasten it by turning clockwise to engage.
The MA887 Digital Refractometer is an optical instrument that employs the measurement of 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 and is easily portable for ship, shore, or home use.
The MA887 Digital Refractometer is an optical instrument that is simple and quick to use. Samples are measured after a simple user calibration with distilled or deionized water. Within seconds, the refractive index and temperature are measured and converted into one of three popular measurement units; Practical Salinity Units (PSU), Salinity in parts per thousand (ppt), or Specific Gravity (S.G. (20/20)).
All conversion algorithms are based upon respected scientific publications using the physical properties of seawater (not sodium chloride). The temperature (in °C or °F) is also displayed on the large dual level display along with helpful message codes.
Key features include:
- Dual-level LCD
- Automatic Temperature Compensation (ATC)
- Easy set up and storage
- Battery operation with Low Power indicator
- Automatically turns off after 3 minutes of nonuse