NIEUWKOOP RE1500 User manual

USER MANUAL
RE1500
REFRACTOMETER DIGITAL
0-85% Brix

RE1500
REFRACTOMETER DIGITAL
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Index
Functional description....................................................................................................................................................................................................................................2
General description............................................................................................................................................................................................................................................4
Specifications ............................................................................................................................................................................................................................................................4
Principle of operation.......................................................................................................................................................................................................................................5
Measuring guidelines.......................................................................................................................................................................................................................................6
Calibration procedure ....................................................................................................................................................................................................................................7
Measurement procedure............................................................................................................................................................................................................................8
Making a standard % brix solution....................................................................................................................................................................................................10
Changing temperature unit ....................................................................................................................................................................................................................11
Error messages........................................................................................................................................................................................................................................................12
Battery replacement.........................................................................................................................................................................................................................................13
Warranty ..........................................................................................................................................................................................................................................................................13

RE1500
REFRACTOMETER DIGITAL
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FUNCTIONAL DESCRIPTION
DISPLAY
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. PRIMARY DISPLAY (DISPLAYS MEASUREMENT AND ERROR MESSAGES)
F. AUTOMATIC TEMPERATURE COMPENSATION (BLINKS WHEN TEMPERATURE EXCEEDS 10-40 °C/
50-104 °F RANGE) TEMPERATURE UNITS
G. TEMPERATURE UNIT
H. SECONDARY DISPLAY (DISPLAYS TEMPERATURE MEASUREMENTS; WHEN BLINKING, TEMPERATURE
HAS EXCEEDED OPERATION RANGE: 0-80 °C / 32-176 °F)

RE1500
REFRACTOMETER DIGITAL
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FRONT PANEL
A E F G
A. LIQUID CRYSTAL DISPLAY (LCD)
B. READ KEY (USER MEASUREMENT)
C. ZERO KEY(USER CALIBRATION)
D. ON/OFF
E. PRIMARY DISPLAY
F. SECONDARY DISPLAY
G. S.STEEL SAMPLE WELL AND PRISM
B C D
BOTTOM
H. BATTERY COVER
I. BATTERY COMPARTMENT

RE1500
REFRACTOMETER DIGITAL
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GENERAL DESCRIPTION
Significance of use
Thank you for choosing this refractometer. This instruction manual will provide you the necessary
information for correct use of the meter.
The RE1500 is an optical instrument that employs the measurement of refractive index to determine
the % Brix of sugar in aqueous solutions. The method is both simple and quick. Samples are measured
after a simple user calibration with deionized or distilled water. Within seconds the instrument
measures the refractive index of the sample and converts it to % Brix concentration units.
The RE1500 digital refractometer eliminates the uncertainty associated with mechanical
refractometers and is easily portable for measurements in the field.
The measurement technique and temperature compensation employ methodology recommended in
the ICUMSA Methods Book (Internationally recognized body for Sugar Analysis).
Temperature (in °C or °F) is displayed simultaneously with the measurement on the large dual level
display along with icons for Low Power and other helpful message codes.
Key features include:
➢Dual-level LCD
➢Automatic Temperature Compensation (ATC)
➢Easy setup and storage
➢Battery operation with Low Power indicator (BEPS)
➢Automatically turns off after 3 minutes of non-use.
The RE1500 refractometer is supplied in a rugged suitcase with:
- 9V battery, syringe and a clear user manual.
TECHNICAL SPECIFICATIONS
Range
0 to 85% Brix / 0 to 80°C
Resolution
0.1% Brix / 0,1 °C
Accuracy
± 0.2% Brix / ±0,3°C
Light source
Yellow LED
Measurement time
± 1.5 seconds
Minimum Sample volume
100 JL (cover prism totally)
Sample Cell
SS ring en glass prism
Temperature Compensation
Automatic between 10 and 40 °C
Case material
ABS
Enclosure rating
IP 65
Battery Type/Live
1 x 9 volt AA battery / 5000 readings
Auto-shut off
After 3 minutes of non-use
Size
23,5 x 21 x 8 cm
Weight
Ca. 660 gram

RE1500
REFRACTOMETER DIGITAL
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PRINCIPE OF OPERATION
The Brix determination is made by measuring the refractive index of a solution. 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. The critical angle can be used to easily
calculate the refractive index according to the equation:
Where n2is the refractive index of the lower-density medium; n1is the refractive index of the higher
density medium.
In the RE1500, light from a 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. The RE1500
automatically applies temperature compensation to the measurement and converts the refractive
index of the sample to sucrose concentration in units of percent (by weight) Brix.

RE1500
REFRACTOMETER DIGITAL
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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 sugar 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.

RE1500
REFRACTOMETER DIGITAL
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CALIBRATION PROCEDURE
Calibration should be performed daily, before measurements are made, when the battery has been
replaced, or between a long series of measurements.
1. Press the ON/OFF key, then release. Two instrument test screens will be displayed briefly; an “all
segment” screen followed by the percentage of remaining battery life. When LCD displays
dashes, the instrument is ready.
2. Using plastic pipettes, fill the sample well with distilled or deionized water.
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 11).
Note: The 0.0 screen will remain until a sample is measured or the power is turned off.
4. Gently absorb the ZERO water standard with a soft tissue. Use care not to scratch the prism
surface. Wipe off the surface completely. The instrument is ready for sample measurement.
Note: If instrument is turned off the calibration will not be lost

RE1500
REFRACTOMETER DIGITAL
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MEASUREMENT PROCEDURE
Verify the instrument has been calibrated before taking measurements.
1. Wipe off prism surface located at the bottom of the sample well.
2. Using plastic pipettes, 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. Measurement is displayed in units of % BRIX.
Note: The ATC tag blinks and automatic temperature compensation is disabled if the temperature
exceeds the 10-40 °C / 50-104 °F range.
4. Remove sample from the sample well by absorbing with a soft tissue.
5. Using plastic pipettes, rinse prism and sample well with distilled or deionized water. Wipe dry.
The instrument is ready for the next sample.

RE1500
REFRACTOMETER DIGITAL
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MAKING A STANDARD % BRIX SOLUTION
To make a Brix Solution, 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 an X BRIX solution weigh out X grams of high purity Sucrose (CAS #: 57-50-1) directly into
the container.
• Add distilled or deionized water to the container so the total weight of the solution is 100g.
• Note: Solutions above 60% Brix need to be vigorously stirred or shaken and heated in a water bath to
roughly 40 °C (104 °F). Remove solution from bath when sucrose has dissolved. Cool completely
before use. The total quantity can be scaled proportionally for smaller containers but accuracy
may be sacrificed.
Example with 25% Brix:
% Brix g Sucrose g Water g Total
25 25.000 75.000 100.000
CHANGING TEMPERATURE UNIT
To change the temperature measurement unit from Celsius to Fahrenheit (or vice versa), follow this
procedure.
1. Press and hold the ON/OFF key continuously for approximately 15 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.
2. While continuing to hold the ON/OFF key, press the ZERO key. The temperature unit will change
from °C to °F or vice versa.

RE1500
REFRACTOMETER DIGITAL
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ERROR MESSAGES
Err
General failure. Cycle power to
instrument. if instrument still has error,
contact Nieuwkoop or your dealer.
LO Top display
Sample is reading lower than the 0%
standard used for meter calibration.
HI Top display
Sample exceeds maximum
measurement range.
LO Top display
Cal segment ON
Wrong calibration used to zero
instrument. Use deionized or distilled
water. Press Zero.
HI Top display
Cal segment ON
Wrong calibration used to zero
instrument. Use deionized or distilled
water. Press Zero.
t LO Top display
Cal segment ON
Temperature exceeds ATC low limit
(10°C) during calibration.
t HI Top display
Cal segment ON
Temperature exceeds ATC high limit
(40°C) during calibration.
Air
Prism surface insufficiently covered.
Elt
Too much external light for
measurement. Cover sample well with
hand.
nLt
LED light is not detected.
Contact Nieuwkoop or your dealer.
Battery segment
blinking
< 5% of battery life is remaining.
Temperature values are
blinking 0.0° or 80.0°C
Temperature measurement out of
sampling range (0.0 to 80.0°C).
ATC segment blinking
Outside temperature compensation
range (10 to 40°C).
SETUP segment blinking
Factory calibration lost.
Contact Nieuwkoop or your dealer.

RE1500
REFRACTOMETER DIGITAL
_____________________________________________________________________________________________
12
BATTERY REPLACEMENT
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 from its location.
• Replace with fresh 9V battery making certain to observe polarity.
• Insert the back battery cover and fasten it by turning clockwise to engage.
For your Safety don’t use or store the instrument in hazardous environments. To avoid
damages or burns, do not perform any measurement in microwave ovens.
WARRANTY
This instrument is warranted against defects in materials and manufacturing for a period of 2
years from the date of purchase. Electrodes are warranted for 6 months. If during this period
the repair or replacement of parts is required, where the damage is not due to negligence or
erroneous operation by the user, please return the instrument, electrode and probe to either
distributor or our office and the repair will be effected free of charge. Damage due to
accidents, misuse, tampering or lack of prescribed maintenance is not covered by the
warranty.
Nieuwkoop BV reserves the right to make improvements in design, construction and
appearance of its products without advance notice.