Westover RHB-18 User manual

Operation Manual
for Westover Model RHB-18
Ô
1) Open daylight plate, and place
2-3 drops of distilled water on
the main prism. Close the
daylight plate so the water
spreads across the entire
surface of the prism without air
bubbles or dry spots. Allow the
sample to rest on the prism for
approximately 30 seconds
before going to step #2. (This
allows the sample to adjust to
the ambient temperature of
the refractometer)
2) Hold daylight plate in the
direction of a light source and
look into the eyepiece. You
will see a circular field with
graduations down the center
(you may have to focus the
eyepiece to see the
graduations clearly). The
upper portion of the field
should be blue, while the
lower portion should be white.
Poor Poor Good
18
16
.
.
.
4
2
0
18
16
.
.
.
4
2
0
3) While looking into the eyepiece,
turn the Calibration Screw until
the boundary between the
upper blue field and the lower
white field meet exactly on the
0.0°. Once complete, the
instrument is calibrated for
your current ambient room
temperature. When working
temperature of the room or
environment (not the sample)
changes by more than 5°F,
we recommend recalibrating
to maintain accuracy and
reproducibility.
As seen when looking
into the instrument
Upper Blue Field
Lower White Field
Boundary Line
adjust to here
Calibration Procedure
Parts Diagram
Daylight Plate
Calibration
Screw
Focus
Adjustment
Main Prism
Assembly
Rubber
Grip
Eyepiece
Hand Held Brix Refractometer
Range: 0-18°
Minimum Division: 0.2°
Accuracy: 0.1°
Dimensions: 27 x 40 160mm
Weight: 176 grams

Warnings - Maintenance
1) Accurate measurement depends on careful calibration. Follow the instructions above closely. Note: Shifts in
ambient room temperature will necessitate recalibration and the sample must be allowed ample time
to adjust to the temperature of the prism prior to measurement. The prism and sample MUST be at the
same temperature for accurate results.
2) Do not expose the instrument to damp working conditions, and do not immerse the instrument in water. If the
instrument becomes foggy, water has entered the body. Call a qualified service technician or contact
you dealer.
3) Clean the instrument between each measurement using a soft, damp cloth. Failure to clean the prism on a
regular basis will lead to inaccurate results and damage to the prism's coating.
5) Do NOT measure abrasive or corrosive chemicals with this instrument. They can damage the prism's coating.
4) This is an optical instrument. It requires careful handling and storage. Failure to do so can result in damage to
the optical components and its basic structure. With care, this instrument will provide years of reliable
Basic Operation
1) Operation is done in essentially
the same manner as
calibration. Open daylight
plate, and place 2-3 drops of
of the liquid sample on the
main prism. Close the
daylight plate so the sample
spreads across the entire
surface of the prism without air
bubbles or dry spots. Allow the
sample to rest on the prism for
approximately 30 seconds
before going to step #2. (This
allows the sample to adjust to
the ambient temperature of
the refractometer)
2) Hold daylight plate in the
direction of a light source and
look into the eyepiece. You
will see a circular field with
graduations down the center
(you may have to focus the
eyepiece to clearly see the
graduations). The upper
portion of the field should be
blue, while the lower portion
should be white.
Poor Poor Good
18
16
.
.
.
4
2
0
18
16
.
.
.
4
2
0
3) Take the reading where the
boundary line of blue and
white cross the graduated
scale. The scale will provide a
direct reading of the Brix
concentration. For use with
non-sugar solutions, see
below. Clean the prism
carefully using a damp soft
cloth. Do NOT immerse in
water. Read warnings below
carefully before use.
As seen when looking
into the instrument
Upper Blue Field
Lower White Field
Boundary Line
Take Reading Here
For Use with Industrial Fluids
The example below is based on using the refractometer with cutting and grinding fluids. The basic principles can be
applied to any number of single solid solutions. For more information, contact your dealer.
1) Prepare a "Gold Standard" solution by carefully diluting a small volume of lubricant using an accurate measuring
cup or graduated cylinder. (e.g. if the manufacturer recommends a 10:1 ratio, pour 10 ounces of water
and 1 ounce of concentrated lubricant into a container)
2) Determine your target reading by measuring this "Gold Standard" with the refractometer. (instructions above)
3) Record your reading for future reference. (e.g. a 10:1 ratio may produce a reading of 2.3° on the instrument)
4) For all future dilution's, use the refractometer to ensure that the new dilution produces the same reading that your
"Gold Standard" produced. (e.g. all future dilution's should read 2.3° on the refractometer)