KERN ORA 90 BE User manual

ORA_90BE_1RE-BA-e-1510
KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen, Germany
E-mail: [e-mail]
Tel: +49-[0]7433-9933-0
Fax: [phone]
Internet: www.kern-sohn.com
Operating manual
Analogue refractometer
KERN ORA 90 BE Analogue Expert
3x Brix scale
KERN ORA 1 RE Analogue Expert
3x nD scale
Version 1.0
01/2015
GB

ORA_90BE_1RE-BA-e-1510 2
GB
KERN ORA
Version 1.0 01/2015
Operating instructions
Analogue refractometer
Contents
1 Technical data................................................................................................ 3
2 Description..................................................................................................... 4
3 General information....................................................................................... 5
3.1 Intended use ............................................................................................................................. 5
3.2 Warranty.................................................................................................................................... 5
4 Basic safety information............................................................................... 6
4.1 Follow the instructions in the operating manual .................................................................. 6
4.2 Warning ..................................................................................................................................... 6
5 Supplied items ............................................................................................... 7
6 Before the first use........................................................................................ 7
7 Use/measurement.......................................................................................... 7
7.1 Additional advice...................................................................................................................... 8
7.2 Measuring procedure............................................................................................................... 9
8 Cleaning and maintenance ......................................................................... 10
9 Storage ......................................................................................................... 10
10 Service.......................................................................................................... 10
11 Disposal........................................................................................................ 10
12 Additional information................................................................................. 10
13 Brix to refractive index (nD) conversion table .......................................... 11
14 Annex.............................................................................................................. 1

3 ORA_90BE-BA-e-1510
1 Technical data
Models
KERN
Measuring
range
and
Scales
Scale gradua-
tions
Accuracy
Dimensions
Product Net weight
ORA 90BE Brix: 0-42%
Brix: 42-71%
Brix: 71-90%
0.2 % Brix
0.2 % Brix
0.2 % Brix
200x40x40mm 0.600kg
ORA 1RE nD: 1. -
1.5200
0.005 nD 200x40x40mm 0.600kg
Example scale on the ORA 90 BE

ORA_90BE_1RE-BA-e-1510 4
2 Description
1. Prism cover
2. Prism surface
3. Adjusting wheel measuring range
4. Dispersion adjusting ring
5. Optical tubes
6. Eyepiece with diopter adjustment ring
7. Storage box
8. Pipette
9. Refractometer
10. Distilled water / calibration liquid
11. Tools
12. Cleaning cloth
2
4
5
3
6
1
12
11
10
9
8
7

5 ORA_90BE-BA-e-1510
3 General information
3.1 Intended use
The refractometer is a measuring instrument for determining the refractive index of
transparent substances in liquid or in some cases also in the solid state. It is used to
observe the behaviour of light as it passes from a prism with known properties to the
substance being tested.
Use of the refractometer for other purposes is contrary to its intended use and may
be hazardous. The manufacturer shall not be liable for any damages caused by im-
proper use.
3.2 Warranty
The warranty shall be void in the event of:
Failure to observe the instructions in the operating manual
Use for purposes other than those described
Modifications or opening the device housing
Mechanical damage and/or damage resulting from media, liquids, natural wear
and tear

ORA_90BE_1RE-BA-e-1510 6
4 Basic safety information
4.1 Follow the instructions in the operating manual
Carefully read through the operating manual even if you have prior
experience with KERN refractometers.
Every language version includes a non-authoritative translation.
The original German document is the definitive version.
4.2 Warning
Do not let acids come into contact with skin or eyes. If acid comes into contact
with skin, flush with copious amounts of water. Shower if larger areas of skin
are affected.
If acid comes into contact with eyes, keep the eyelid open and flush the eye
with running lukewarm water from the outer corner to the inner corner. Flush
eyes for at least 15 minutes. Then consult a doctor or ophthalmologist imme-
diately.
Thoroughly clean the refractometer after each use.
The refractometer must not be exposed to extreme temperatures, high me-
chanical stresses, strong direct sunlight or high humidity.
This refractometer is not a toy. Keep out of reach of children.
Make sure that you will not be hit by anything else while you are using the re-
fractometer, as this could cause serious eye injuries
The rubber eyeshade may cause irritation when in prolonged contact with the
skin. If this happens, consult your doctor.
Do not touch the lenses with your fingers.

7 ORA_90BE-BA-e-1510
5 Supplied items
After unpacking and before using the device for the first time, check that all listed
parts have been supplied. Replace damaged or faulty parts immediately and do not
put them into operation.
Refractometer
Storage box
Pipette
Tools
Cleaning cloth
6 Before the first use
Remove the protective film (if present) from the prism surface [2] and move the
measuring range adjusting wheel [3] to position 1.
7 Use/measurement
The refractometer can be used to quickly and accurately determine the refractive in-
dex of transparent substances, liquid or solid ones. Please make sure your hands are
dry before handling the measuring device.
The measuring instrument has three measuring ranges. Please use the measuring
range adjusting wheel on the underside of the casing to switch measuring ranges.
The light falling on the prism can be changed using a rotating flap on the underside of
the prism.
In addition, the refractometer is provided with an adjusting ring [4], which can reduce
chromating, primarily with low liquid concentrations.
The light/dark transition is clearly visible.

ORA_90BE_1RE-BA-e-1510 8
Important!
The ambient/room temperature and the sample temperature influence the refracto-
meter 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 13.
7.1 Additional advice
It is important that the samples being measured are representative samples. Meas-
urements should be carried out quickly on samples that evaporate easily. The sam-
ples should be at the same temperature as the measuring instrument in order to
achieve an accurate result.

9 ORA_90BE-BA-e-1510
7.2 Measuring procedure
Make sure your hands are dry before handling the refractometer.
Open the prism cover [1] and use the supplied pipette [8] to apply a few drops
of the sample liquid [8] onto the prism surface [2], then close the prism cover
[1]. Spread the liquid evenly by pressing down on the prism cover [1].
Hold the device horizontally and wait about 30 seconds (for optimal tempera-
ture equalisation between the sample and device).
View the measurement scale through the eyepiece [6]. Point the prism surface
[2] of the refractometer at a bright light source while doing this.
The light falling on the prism can be changed using a rotating flap on the un-
derside of the prism.
Rotate the adjustment ring [6] on the eyepiece [6] to adjust the focus.
The boundary line will move on the measurement scale depending on the
concentration. This bright/dark boundary line shows the result directly on the
scale.
The measuring instrument has three measuring ranges. Please use the
measuring range adjusting wheel on the underside of the casing to switch
measuring ranges.
The light/dark boundary can be brought into sharp focus using the dispersion
adjusting ring [6]. This is useful for low liquid concentrations.
If the temperature deviates from +20 °C, correct the measured result using the
corresponding value from the temperature correction table [13].
Carefully clean the supplied pipette [8] and the refractometer after carrying out
the measurement.
Important!
After every measurement, use a lint-free, absorbent cloth to remove the fluids from
the prism surface [2] and prism cover [1]. Then carefully clean the prism and prism
cover using a cloth moistened with water or if necessary alcohol, and dry both parts
using a soft, dry and lint-free cloth. Avoid rubbing the prism [2].

ORA_90BE_1RE-BA-e-1510 10
8 Cleaning and maintenance
Clean the refractometer using a soft, lint-free cloth moistened with water, or if neces-
sary 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 with wet
or damp hands.
Never touch the measuring prism [2] with hard tools made from plastic, wood, rubber,
metal, glass etc. Hard objects can quickly damage the relatively soft prism glass, re-
sulting in measurement errors.
The refractometer is maintenance-free.
Cleaning should be carried out immediately before and after each use of the refrac-
tometer to maximise its life and optimise measurement results.
9 Storage
Store the refractometer in a dry, non-corrosive environment, preferably between
10°C and 30 °C.
10 Service
After 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
authorised by KERN.
11 Disposal
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. We reserve the right to make
changes to reflect technical advancements, decorations not included.
Avoid exposing the refractometer to direct sunlight!
Never bring the refractometer into contact with solvents.