7.1 Zero point calibration
▸ Hold up the refractometer against a sufficiently bright light source and look through
, holding the eyepiece closely against your eye/glasses.
to adjust it for your eyesight, until you can see the scale
▸ Thoroughly clean the prism
and the underside of the prism cover
with alcohol if necessary
and wipe dry. Water should only ever
be applied to the measuring prism, not to other parts of the device.
▸ Now apply a few drops of the calibration liquid
. The amount of fluid should be sufficient to moisten most of
the prism surface. There should not be any air bubbles between the measuring prism
▸ Wait about 30 seconds to allow the temperatures of the test fluid and prism to
▸ Look through the eyepiece
while pointing the refractometer‘s prism surface
, you will see a bright and a blue field. The boundary line
between them shows the refractive index value on the scale which is also visible
▸ With the aid of the supplied adjustment tool
to turn the adjustment screw
at the side of the prism surface
he scale can be adjusted so that the
measuring evice is optimally set up d by moving the boundary line upwards or
Calibration value: 0 % (Brix)
▸ For refractometers without automatic temperature compensation
sured value to take account of the deviation in room and sample
temperature rom +20 °C. f
See the table at the end of this manual, Point 1 .4
The ambient/room temperature and the sample temperature influence
the refractometer measuring result.
The scales are designed for an ambient temperature of +20 °C!
If the measurements are carried out at a temperature other than +20
°C, the results must be correspondingly corrected.
A correction table can be found in the annex, Point 1 .4
It is important that the samples being measured are representative samples. Meas-
urements should be carried out quickly on samles that evaporate easily.If possible,
the samples should be at the same temperature as the measuring instrument in order
to achieve an accurate result.
▸ Make sure your hands are dry before handling the refractometer.
and use the supplied pipette
, then close the prism cover
Spread the liquid evenly by pressing down on the prism cover
▸ Hold the device horizontally and wait about 30 seconds
equalisation between the sample and device
▸ View the measurement scale through the eyepiece
. Point the prism surface
of the refractometer at a bright light source while doing this.
▸ Rotate the adjustment ring
▸ The boundary line will move on the measurement scale depending on the concen-
tration. This bright/dark boundary line shows the result directly on the scale.
▸ If the temperature deviates from +20 °C, correct the measured result using the
corresponding value from the temperature correction table
▸ Carefully clean the supplied pipette
and the refractometer aer carrying out
Aer every measurement, use a lint-free, absorbent cloth to remove
the fluids from the prism surface
carefully clean the prism and prism cover using a cloth moistened
with water and dry both parts using a so, dry and lint-free cloth. Avoid rubbing the
8. Cleaning and maintenance
Clean the refractometer using a so, lint-free cloth moistened with water, or if
necessary alcohol. Do not use any aggressive or abrasive cleaning agents. Never
immerse the device in water or hold it under running water. Never handle the device
Never touch the measuring prism
with hard tools made from plastic, wood,
rubber, metal, glass etc. Hard objects can quickly damage the relatively so prism
glass, resulting in measurement errors.
The refractometer is maintenance-free.
Cleaning should be carried out immediately before and aer each use of the
refractometer to maximise its life and optimise measurement results.
Store the refractometer in a dry, non-corrosive environment, preferably
Aer reading this operating manual, if you have any questions about setting up or
using the refractometer, or if any unexpected problem occurs, please contact your
dealer. The device housing may only be opened by trained service technicians
The packaging consists of environmentally friendly materials which can be disposed
of via local recycling facilities.
The device and storage box should be disposed of by the operator in accordance
with applicable national or regional regulations at the place of use.
12. Additional information
The product may differ slightly from the illustrations.
Avoid exposing the refractometer to direct sunlight.
Never bring the refractometer into contact with solvents.
13. Brix to refractive index (nD) conversion table
Data from „ICUMSA“ International Commission for Uniform Methods
of Sugar Analysis, at 20 °C and 589 nm wavelength.
Table 1: International Temperature Correction Table for °Brix
Correct the result by the following values
refractometer must be correctly
BRIX
Refractive
index BRIX
Refractive
index BRIX
Refractive
index
% % % nD nD nD
1 1.33442 31 1.38296 61 1.44420
2 1.33586 32 1.38478 62 1.44650
3 1.33732 33 1.38661 63 1.44881
4 1.33879 34 1.38846 64 1.45113
6 1.34175 36 1.39220 66 1.45584
7 1.34325 37 1.39409 67 1.45822
8 1.34476 38 1.39600 68 1.46061
9 1.34629 39 1.39792 69 1.46303
10 1.34782 40 1.39986 70 1.46546
11 1.34937 41 1.40181 71 1.46792
12 1.35093 42 1.40378 72 1.47037
13 1.35250 43 1.40576 73 1.47285
14 1.35408 44 1.40776 74 1.47535
15 45 1.40978 75 1.47787 1.35568
16 1.35729 46 1.41181 76 1.48040
17 1.35891 47 1.41385 77 1.48295
18 48 1.41592 78 1.48552 1.36054
19 49 1.41799 79 1.4881 1.36218
20 50 1.42009 80 1.49071 1.36384
21 51 1.42220 81 1.49333 1.36551
22 52 1.42432 82 1.49597 1.36720
23 53 83 1.36889 1.42647 1.49862
25 1.37233 55 1.43080 85 1.50398
26 1.37406 56 1.43299
27 1.37582 57 1.43520
28 1.37758 58 1.43743
0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 55.0 60.0 65.0 70.0 75.0 80.0 85.0
Temperature °C
- - - - - - - - - - - - - - - - - - 0.53 0.56 0.59 0.62 0.65 0.67 0.69 0.71 0.72 0.73 0.74 0.75 0.75 0.75 0.75 0.75 0.74 0.73
- - - - - - - - - - - - - - - - - - 0.49 0.52 0.54 0.57 0.59 0.61 0.63 0.64 0.65 0.66 0.67 0.68 0.68 0.68 0.68 0.67 0.67 0.66
- - - - - - - - - - - - - - - - - - 0.44 0.47 0.49 0.51 0.53 0.55 0.56 0.57 0.58 0.59 0.60 0.60 0.61 0.61 0.60 0.60 0.60 0.59
- - - - - - - - - - - - - - - - - - 0.40 0.41 0.43 0.45 0.47 0.48 0.50 0.51 0.52 0.52 0.53 0.53 0.53 0.53 0.53 0.53 0.52 0.52
- - - - - - - - - - - - - - - - - - 0.34 0.36 0.38 0.39 0.40 0.42 0.43 0.44 0.44 0.45 0.45 0.46 0.46 0.46 0.46 0.45 0.45 0.44
- - - - - - - - - - - - - - - - - - 0.29 0.31 0.32 0.33 0.34 0.35 0.36 0.37 0.37 0.38 0.38 0.38 0.38 0.38 0.38 0.38 0.37 0.37
- - - - - - - - - - - - - - - - - - 0.24 0.25 0.26 0.27 0.28 0.28 0.29 0.30 0.30 0.30 0.31 0.31 0.31 0.31 0.31 0.30 0.30 0.30
- - - - - - - - - - - - - - - - - - 0.18 0.19 0.20 0.20 0.21 0.21 0.22 0.22 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.23 0.22
- - - - - - - - - - - - - - - - - - 0.12 0.13 0.13 0.14 0.14 0.14 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15 0.15
- - - - - - - - - - - - - - - - - - 0.06 0.06 0.07 0.07 0.07 0.07 0.07 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.07
0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00
0.06 0.07 0.07 0.07 0.07 0.07 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.08 0.07
0.13 0.14 0.14 0.14 0.15 0.15 0.15 0.15 0.16 0.16 0.16 0.16 0.16 0.16 0.15 0.15 0.15 0.15
0.20 0.21 0.21 0.22 0.22 0.23 0.23 0.23 0.23 0.24 0.24 0.24 0.24 0.23 0.23 0.23 0.23 0.22
0.27 0.28 0.29 0.29 0.30 0.30 0.31 0.31 0.31 0.32 0.32 0.32 0.32 0.31 0.31 0.31 0.30 0.30
0.34 0.35 0.36 0.37 0.38 0.38 0.39 0.39 0.40 0.40 0.40 0.40 0.40 0.39 0.39 0.39 0.38 0.37
0.42 0.43 0.44 0.45 0.46 0.46 0.47 0.47 0.48 0.48 0.48 0.48 0.48 0.47 0.47 0.46 0.46 0.46
0.50 0.51 0.52 0.53 0.54 0.55 0.55 0.56 0.56 0.56 0.56 0.56 0.56 0.55 0.55 0.54 0.53 0.52
0.58 0.59 0.60 0.61 0.62 0.63 0.64 0.64 0.64 0.65 0.65 0.64 0.64 0.64 0.63 0.62 0.61 0.60
0.66 0.67 0.68 0.69 0.70 0.71 0.72 0.73 0.73 0.73 0.73 0.73 0.72 0.72 0.71 0.70 0.69 0.68
0.74 0.75 0.77 0.78 0.79 0.80 0.81 0.81 0.81 0.82 0.81 0.81 0.81 0.80 0.79 0.78 0.77 0.75
