Installing batteries
Remove the battery compartment cover by turning
the two retaining screws in an anti-clockwise
direction. Before inserting the batteries check that
the compartment is clean and dry, and that the
cover seal is in good order. Insert the batteries,
ensuring that the battery polarity is correct.
Replace the cover by turning the two retaining
screws in a clockwise direction whist the cover is
in position.
It is recommended that alkaline batteries are used
to reduce the frequency of battery changes. It is
also recommended that the batteries should be
removed during international transit or for long
periods without use.
The battery indicator will show the current
state of the batteries. When the indicator
shows empty replace the batteries.
Turning on and off
Press READ to turn the refractometer on.
The instrument will automatically turn off if no
keys are pressed for 60 seconds. Alternatively
press and hold READ for 3 seconds to switch the
instrument off.
Basic operation
Instrument overview
Manufacturer’s details
Safety precautions
Thank you for purchasing this Digital Hand Held
Refractometer. In order to ensure that this product
provides many years of service please follow the
guidance in this document.
Type A
Cat No. 635-0722
0-54 Brix
1.33-1.42 RI
Type B
Cat No. 635-0723
0-95 Brix
1.33-1.54 RI
Unpacking the instrument
Check that all parts listed below are present and
that no transit damage has occurred.
Contents list
1 VWR Digital Hand Refractometer (Type A or B)
2 AAA alkaline battery (LR03)
1 User guide
www.vwr.com
WARNINGS
Always check the relevant Material Safety Data Sheet for a sample before applying it to the refractometer.
Wear appropriate protective equipment (PPE) when applying samples that may be harmful to the skin or
eyes. Avoid unnecessary contamination of the refractometer by confining samples to the prism dish.
CAUTION
This refractometer is a precision optical instrument and should be handled with care. Do not drop or
subject the instrument to sharp knocks. The instrument housing and display panel areas are constructed
from plastic materials that may suffer damage if contacted with aggressive organic solvents. For example,
avoid contact with solvents such as acetone and certain aromatic solvents.
Maintain your refractometer in a clean condition and avoid use and storage of the instrument outside the
specified temperature range. Avoid dusty and high humidity environments and prolonged exposure to
direct sunlight. Use the soft case provided to protect the instrument. Deterioration/loss of the display may
be indicative of low battery power or low ambient temperature. Do not persist in using the instrument with
low battery power. Check/replace the batteries as necessary.
Error messages
In order to achieve the maximum performance from the refractometer, it is essential that care is taken
when cleaning the instrument and applying sample to the prism. Sample concentration may vary
considerably from the surface to the centre of a mass whether in a beaker or on a spoon or spatula.
Evaporation will cause the reading to drift unless care is taken.
Measured sample out of range.
Sample either too low or high or of insufficient volume
Temperature too low or high.
Battery too low
Excessive ambient light (-HAL-) or insufficient sample
No recorded temperature
AG Test Mode is active
Warranty and customer care
VWR International warrants that this product will be free from defects in material and workmanship for
a period of two (2) years from date of delivery. If a defect is present, VWR will, at its option and cost,
repair, replace, or refund the purchase price of this product to the customer, provided it is returned
during the warranty period.
This warranty does not apply if the product has been damaged by accident, abuse, misuse, or
misapplication, or from ordinary wear and tear. If the required maintenance and inspection services are
not performed according to the manuals and any local regulations, such warranty turns invalid, except to
the extent, the defect of the product is not due to such non-performance.
Items being returned must be insured by the customer against possible damage or loss. This warranty
shall be limited to the aforementioned remedies.
IT IS EXPRESSLY AGREED THAT THIS WARRANTY WILL BE IN LIEU OF ALL WARRANTIES OF
FITNESS AND IN LIEU OF THE WARRANTY OF MERCHANTABILITY.
Manufactured in the UK
VWR International, Leuven, Belgium
www.vwr.com
Prism dish
Prism surface
LCD display
ZERO key
READ key
Battery
indicator
Scale identifiers
Battery compartment cover
Model / scale
identification label
The refractometer has a number of special
features that allow the user to configure and verify
the way the instrument operates.
Def
initions
“-AGt-“ Test Mode
“-tSc-“ Temperature scale selection mode
Changing the temperature display
The refractometer may be configured to display the
temperature in either Celsius (°C) or
Fahrenheit (°F)
1. Press and HOLD the READ key until OFF is
displayed
2. Quickly release the READ key
3. Press and RELEASE the ZERO key (“-AGt“
will be displayed – see “AG Test Mode”)
4. Press ZERO
5. “-tSc-“ will be displayed
6. Press READ until the desired temperature
scale is selected
7. Press ZERO to select the displayed
temperature format
Verifying the instrument using a
sucrose solution
The measurement performance of the
refractometer may be verified using a sucrose
solution (weight/weight) of known concentration:
1. Perform a zero calibration
2. Fill the prism dish with the sample
3.
Allow sufficient time for temperature stabilisation
(typically 10 seconds)
4. Press READ
5. The refractometer may be considered to be
performing correctly if the reading is equal to
the concentration of the sucrose solution ±0.2
°Brix (or equivalent for non-Brix models)
If the instrument is found to be out of specification,
repeat the test and if necessary contact the
manufacturer for further advice.
Verifying the instrument using the
“AG Test Mode”
As an alternative to using a sucrose based
solution of limited shelf life, the refractometer
may be verified using a convenient “long-life” AG
Fluid. However, as the AG Fluid is not sucrose
based, it cannot be corrected for temperature
using ICUMSA (sucrose) compensation, so the
refractometer incorporates a special “Test Mode”
to facilitate the use of the AG Fluids as follows:
1. Perform a zero calibration
2. Press and HOLD the READ key until OFF is
displayed
3. Quickly release the READ key
4. Press and RELEASE the ZERO key “-AGt-“ will
be displayed (This is the “AG Test Mode”)
5.
Press the READ key (“-AGt-“ flashes)
6. Fill the prism dish with the AG Fluid
7.
Allow sufficient time for temperature stabilisation
(typically 10 seconds)
8. Press READ (The instrument will alternate
between the result and “-AGt-“ to indicate that it
is in the “Test Mode”
9. The refractometer may be considered to be
performing correctly if the reading is equal to the
concentration of the AG Fluid ±0.2 °Brix
10. Turn OFF the instrument to EXIT the Test Mode
If the instrument is found to be out of specification,
repeat the test and if necessary contact the
manufacturer for further advice.
Special features
(flashes)
Taking a reading
Before taking a reading clean the prism surface
thoroughly using a suitable solvent, eg water or
methyl alcohol depending on the sample being
measured.
1. Fill the prism dish
2. Press READ – the display will clear
3. A few seconds later the reading will be
displayed
After a measurement has been taken the sample
should be removed and the prism cleaned.
Zero calibration
The zero calibration is essential to ensure
accurate readings. A zero calibration should be
carried out daily.
Use distilled water if possible. Should tap water
be used please be aware that subsequent
measurement accuracy may vary depending upon
the purity of the tap water.
1. Clean and dry the prism
2. Fill the sample dish with water
3.
Allow sufficient time for temperature
stabilisation (typically 10 seconds)
4. Press and HOLD the ZERO key for 4 seconds
5. The display will show “ooo” as the calibration
starts
6. When complete the display will show “000”
Remember to hold the ZERO key for
4 seconds when calibrating with water
Displaying the temperature
The refractometer can display the temperature of
the last reading:
1. Quickly press & RELEASE the ZERO key
2. The temperature will be displayed in
the configured scale (see “changing the
temperature display” in the “Special Features”
section)
3. NOTE: If a reading has not be taken the
display will show “--.-°C” (or °F if selected)
Changing the measurement scale
The refractometer has two measurement scales
as indicated on the Certificate of Calibration. The
selected scale will be indicated by an arrow on the
display. To change the scale:
1. Press and HOLD the ZERO key
2. Within 3 seconds PRESS and RELEASE the
READ key to toggle between the scales until
the desired measurement scale is selected
Changing scale requires the ZERO key to
be held. Holding the ZERO key for longer
than specified will cause a zero calibration to be
performed!
(alternates)
Automatic temperature compensation
Automatic temperature compensation will correct readings of water and sucrose solutions to 20°C. It
conforms to the published ICUMSA 1978 correction tables which covers the ranges 10 to 40°C and 0
to 80° Brix and has been extended to cover 5 to 70°C by using additional data. Although the correction
is specifically applicable to pure sucrose solutions, it is also valid for many sugar based food products.
However, it must be stressed that the correction values may be unsuitable for other non-sugar based
products and great care should be exercised with these samples.
This symbol is an internationally
agreed indicator that the product
bearing it should not be disposed of
as general waste or garbage which
might end up in landfill sites, but
should instead be sent for special
processing and/or recycling in
those countries where appropriate
legislation and facilities are in place.
This symbol indicates a caution or
warning, please refer to the manual.
Digital Hand Held Refractometer
INTENDED USE
This product is for general laboratory, manufacturing and research use only and is not intended for any
animal or human therapeutic or diagnostic use.
EN
General specification
Prism and dish
Dish material
316 stainless steel
Prism seal
Silicone rubber and Viton
Prism material Optical glass
Sample surface 8 mm diameter
Housing
Material
Acrylonitrile Butadiene Styrene
IP rating
IP65 water resistant
Relative humidity 95% RH
Measurement
Range (°Brix / RI) (Type A) 0-54 / 1.33-1.42
(Type B) 0-95 / 1.33-1.54
Resolution (°Brix / RI)
0.1 / 0.0001
Accuracy (°Brix / RI)
±0.2 / ±0.0003
Physical
Length
115 mm
Width
54 mm
Height
30 mm
Weight
85g (without batteries fitted)
Temperature
Storage
-10 to 60°C
Operating
5 to 40°C
Brix measurement
5 to 60°C
RI measurement
5 to 40°C
