Milwaukee MA887 User manual

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MA887
Refractometer for SeawaterRefractometer for Seawater
Refractometer for SeawaterRefractometer for Seawater
Refractometer for Seawater
MeasurementsMeasurements
MeasurementsMeasurements
Measurements
Milwaukee RefractometerMilwaukee Refractometer
Milwaukee RefractometerMilwaukee Refractometer
Milwaukee Refractometer
INSTRUCTION MANUAL
Test Equipment Depot - 800.517.8431 - 99 Washington Street Melrose, MA 02176
TestEquipmentDepot.com

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Instruction Manual MA887 Refractometer for Seawater Measurements
FUNCTIONAL DESCRIPTION ............................................................................. 3
GENERAL DESCRIPTION .................................................................................... 5
SPECIFICATIONS .............................................................................................. 6
PRINCIPLE OF OPERATION ................................................................................ 6
MEASUREMENT GUIDELINES .............................................................................. 8
CALIBRATION PROCEDURE ............................................................................... 8
MEASUREMENT PROCEDURE ........................................................................... 10
CHANGING MEASUREMENT UNIT ................................................................... 11
CHANGING TEMPERATURE UNIT ..................................................................... 12
MAKING A STANDARD SODIUM CHLORIDE SOLUTION .................................... 12
ERROR MESSAGES ........................................................................................... 13
BATTERY REPLACEMENT ................................................................................... 14
WARRANTY ..................................................................................................... 15
TABLE OF CONTENTS
Remove the instrument from the packing materials and examine carefully to
ensure no damage has occurred during shipping. If any damage has
occurred, notify your Dealer.
Each instrument is supplied with:
• 9 V battery
• Instruction manual
Note: Save all packing material until you are sure that the instrument
functions correctly. A defective instrument must be returned in its
original packing.

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FUNCTIONAL DESCRIPTION
A. BATTERY STATUS ICON (BLINKS WHEN LOW BATTERY CONDITION DETECTED)
B. MEASUREMENT IN PROGRESS TAG
C. SETUP: FACTORY CALIBRATION TAG
D. CAL: CALIBRATION TAG
E. AUTOMATIC TEMPERATURE COMPENSATION
(BLINKS WHEN TEMPERATURE EXCEEDS 10-40 °C / 50-104 °F RANGE)
F. PRIMARY DISPLAY (DISPLAYS MEASUREMENT AND ERROR MESSAGES)
G. TEMPERATURE UNITS
H. SECONDARY DISPLAY (DISPLAYS TEMPERATURE MEASUREMENTS; WHEN BLINKING,
TEMPERATURE HAS EXCEEDED OPERATION RANGE: 0-80 °C / 32-176 °F)
I. RANGE INDICATOR
DISPLAYDISPLAY
DISPLAYDISPLAY
DISPLAY

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Instruction Manual MA887 Refractometer for Seawater Measurements
I. BATTERY COVER
J. BATTERY COMPARTMENT
BOTTOMBOTTOM
BOTTOMBOTTOM
BOTTOM
A. LIQUID CRYSTAL DISPLAY (LCD)
B. READ KEY (USER MEASUREMENT)
C. ZERO KEY (USER CALIBRATION)
D. RANGE KEY (USER MEASUREMENT UNIT)
E. ON/OFF
F. STAINLESS STEEL SAMPLE WELL AND PRISM
G. SECONDARY DISPLAY
H. PRIMARY DISPLAY
FRONT PANELFRONT PANEL
FRONT PANELFRONT PANEL
FRONT PANEL

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GENERAL DESCRIPTION
SIGNIFICANCE OF USE
Thank you for choosing Milwaukee. This instruction manual will provide you the
necessary information for correct use of the meter.
The MA887 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 interme-
diates. The digital refractometer eliminates the uncertainty associated with mechanical
refractometers and is easily portable for ship, shore or home use.
The MA887 refractometer is an optical device 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:
• Waterproof models offers IP65 waterproof protection
• Automatic Temperature Compensation (ATC)
• Battery operation with Low Power indicator
• Automatically turns off after 3 minutes of non-use.

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Instruction Manual MA887 Refractometer for Seawater Measurements
PRINCIPLE OF OPERATION
Light Source Yellow LED
Measurement Time Approximately 1.5 seconds
Minimum Sample Volume 100 μL (cover prism totally)
Sample Cell Stainless Steel ring and flint glass prism
Temperature Compensation Automatic between 0 and 40 °C (32 to 104 °F)
Case Material ABS
Enclosure Rating IP 65
Battery Type/Life 1 x 9 volt AA batteries / 5000 readings
Auto-Shut off After 3 minutes of non-use
Dimensions 19.2 x 10.2 x 6.7 cm (7.5 x 4 x 2.6")
Weight 420 g (14.8 oz.).
SPECIFICATIONS
USPtpp)02/02(.G.S)F°(C°
:egnaR 05ot0051ot0411.1ot000.1)F°671ot23(C°08ot0
:noituloseR 11 100.0)F°1.0(C°1.0
:ycaruccA 2
±2±200.0±)F°5.0±(C°3.0±
Salinity determinations are made by measuring the refractive index of seawater. Refractive
Index is an optical characteristic of a substance and the number of dissolved particles in
it. Refractive Index is defined as the ratio of the speed of light in empty space to the speed
of light in the substance. A result of this property is that light will “bend”, or change
direction, when it travels through a substance of different refractive index. This is called
refraction.
When passing from a material with a higher to lower refractive index, there is a critical
angle at which an incoming beam of light can no longer refract, but will instead be
reflected off the interface.

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The critical angle can be used to easily calculate the refractive index according to the
equation:
sin (θcritical) = n2/ n1
Where n2is the refractive index of the lower-density medium; n1is the refractive index of
the higher-density medium.
In the MA887 refractometer, light from an LED passes through a prism in contact with the
sample. An image sensor determines the critical angle at which the light is no longer
refracted through the sample. Specialized algorithms then apply temperature
compensation to the measurement and convert the refractive index to: PSU (Practical
Salinity Units), ppt (part per thousand) or S.G. (Specific Gravity) (20/20). PSU is defined
as the conductivity ratio of seawater to a standard KCl solution. It is based upon the work
of the UNESCO, ICES, SCOR and IAPSO. This information is published in The Joint
Panel of Oceanographic Tables and Standards. An older salinity scale is ppt (10-3), where
salinity is defined by “the salt content is the weight of the inorganic salts contained in 1
kg of seawater if all bromide and iodide are replaced by an equivalent amount of oxides”
(Knudsen, 1901).

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Instruction Manual MA887 Refractometer for Seawater Measurements
CALIBRATION PROCEDURE
MEASUREMENT GUIDELINES
• 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.
1. 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 measurement unit set. When the
LCD displays dashes, the instrument is ready.
Specific Gravity (20/20) ia based upon the published relationship between density at
20 °C and the mass of dissolved salts in the seawater sample (CRC Handbook of
Chemistry and Physics, 87th)Edition).

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2. 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.
3. Press the ZERO key. If no error messages appear, your unit is calibrated.
(For a description of ERROR MESSAGES see page 13).
Note: The 0 screen will remain until a sample is measured or the instrument is turned off.
4. 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 instrument is turned off the calibration will not be lost.

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Instruction Manual MA887 Refractometer for Seawater Measurements
MEASUREMENT PROCEDURE
Verify the instrument has been calibrated before taking measurements.
1. Wipe off prism surface located at the bottom of the sample well. Make sure the prism
and sample well are completely dry.
2. Using a plastic pipette, drip sample onto the prism surface. Fill the well completely.
Note: If the temperature of the sample differs significantly from the temperature of the
instrument, wait approximately 1 minute to allow thermal equilibration.
3. Press the READ key. The results are displayed in unit of interest.
Note: The last measurement value will be displayed until the next sample is measured
or the instrument is turned off. Temperature will be continuously updated.
Note: The “ATC” tag blinks and automatic temperature compensation is disabled if the
temperature exceeds the 0-40 °C / 32-104 °F range.
4. Remove sample from the sample well by absorbing on a soft tissue.