KERN Optics ORA 2SA User manual

KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen, Germany
E-mail: [e-mail]
Tel: +49-[0]7433-9933-0
Fax: +49-[0]7433-9933-149
Internet: www.kern-sohn.com
Operating manual
Analogue refractometer
KERN ORA 1 SA Seawater
salinity
ORA 2 SA NaCL%
ORA 3 SA NACL% Brix%
Version 1.0
01/2015
GB

ORA-1SA-2SA-3SA-BA-e-1510 2
GB
KERN ORA
Version 1.0 01/2015
Operating manual
Analogue refractometer
Contents
1 Technical data................................................................................................ 3
2 Device parts and 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 Zero point calibration............................................................................................................... 8
7.2 Automatic temperature compensation (ATC)........................................................................ 8
7.3 Additional advice...................................................................................................................... 9
7.4 Measuring procedure............................................................................................................... 9
8 Cleaning and maintenance ......................................................................... 10
9 Storage ......................................................................................................... 10
10 Service.......................................................................................................... 10
11 Disposal........................................................................................................ 10
12 Additional information................................................................................. 10

3 ORA-1SA-2SA-3SA-BA-e-1510
1 Technical data
Model
Measuring
range Accuracy Dimensions (mm) Weight (g)
ORA 1 SA 0-100‰
1.000-1.070 1‰ 0.005 27 x 40 x 190 175
ORA 2 SA 0-28% 0.2% 27 x 40 x 160 175
ORA 3 SA 0-28% NaCl
0-32% Brix 0.2 % 0.2 % 27 x 40 x 160 175
Example scale on the ORA 2 SA

ORA-1SA-2SA-3SA-BA-e-1510 4
2 Device parts and description
1. Prism cover
2. Prism surface
3. Adjustment screw
4. Eyepiece with rubber eyeshade
5. Diopter adjustment ring
6. Optical tubes with rubber grip
7. Storage box
8. Pipette
9. Refractometer
10. Distilled water / calibration liquid
11. Adjustment tool
12. Cleaning cloth
1
6
3
5
4
2
7
10
9
11
12
8

5 ORA-1SA-2SA-3SA-BA-e-1510
3 General information
3.1 Intended use
The refractometer is a measuring device for determining the refractive index of
transparent substances in liquid or in some cases also in 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
improper 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-1SA-2SA-3SA-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.
The original document in German is the definitive version. All other
language versions are non-authoritative translations.
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
immediately.
Thoroughly clean the refractometer after each use.
The refractometer must not be exposed to extreme temperatures, high
mechanical 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
refractometer, 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-1SA-2SA-3SA-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
Adjustment tool
Cleaning cloth
Distilled water / calibration fluid
6 Before the first use
Remove the protective film (if present) from the prism surface [2] and check that the
rubber eyeshade [4] is fitted correctly.
7 Use / measurement
The refractometer can be used to quickly and accurately determine the refractive
index of transparent substances, liquid or solid ones. To ensure correct
measurement, the measuring device should be adjusted before measurements are
carried out. Please make sure your hands are dry before handling the measuring
device.

ORA-1SA-2SA-3SA-BA-e-1510 8
7.1 Zero point calibration
Hold up the refractometer against a sufficiently bright light source and look
through the eyepiece [5], holding the rubber eyeshade [4] closely against your
eye/glasses.
Rotate the eyepiece [5] to adjust it for your eyesight, until you can see the
scale sharply.
Open the prism cover [1].
Thoroughly clean the prism [2] and the underside of the prism cover [1] using
a soft cloth or soft paper (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 [10] onto the prism surface [2].
close the prism cover [1]. 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 [2] and prism cover [1].
Wait about 30 seconds to allow the temperatures of the test fluid and prism to
equalise.
Look through the eyepiece [4] while pointing the refractometer's prism surface
[2] at a bright light source.
Through the eyepiece [4], 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 through the eyepiece [4].
Use the supplied adjustment tool [11] to turn the adjustment screw [3] behind
the prism surface [2] (under the rubber cap), and adjust the scale so that the
measuring device is optimally set up. The bright/dark boundary line should be
at 0% Brix. For refractometers which are not set to 0% Brix using distilled
water and have a special calibration fluid, set the bright/dark boundary line to
the calibration line in the prism. The room temperature should be +20°C.
For refractometers without automatic temperature compensation (ATC):
Convert the measured value to take account of the deviation in room and
sample temperature from +20 °C. (See the table in section 13 at the end of
this instruction manual.)
Repeat step 4 (cleaning).
7.2 Automatic temperature compensation (ATC)
Automatic temperature compensation (ATC).
The handheld refractometer is equipped with automatic temperature compensation.
This automatically compensates for measurement differences resulting from
differences in sample temperatures. It operates between +10 °C and +30 °C.
ATC eliminates the need to convert values using a temperature correction table.

9 ORA-1SA-2SA-3SA-BA-e-1510
7.3 Additional advice
It is important that the samples being measured are representative samples. For
samples that evaporate easily, measurements should be carried out quickly. If
possible, the samples should be at the same temperature as the measuring device to
achieve an accurate measurement result.
7.4 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 onto the prism surface [2], then close the prism cover [1].
Spread the liquid evenly by slightly pressing down the prism cover [1].
Hold the device horizontally and wait about 30 seconds (for optimal
temperature equalisation between the sample and device).
View the measurement scale through the eyepiece [4]. Point the prism surface
[2] of the refractometer at a bright light source while doing this.
Rotate the adjustment ring [5] on the eyepiece [4] 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 on the scale.
If the temperature deviates from +20 °C, correct the measured result using the
corresponding value from the temperature correction table (see section 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-1SA-2SA-3SA-BA-e-1510 10
8 Cleaning and maintenance
Clean the refractometer using a clean, 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
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,
resulting in measurement errors.
The refractometer is maintenance-free.
Cleaning should be carried out immediately before and after each use of the
refractometer to maximise its life and optimise measurement results.
9 Storage
Store the refractometer in a dry, non-corrosive environment.
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.
Avoid exposing the refractometer to direct sunlight.
Never bring the refractometer into contact with solvents.