KERN ORA 1 GG User manual

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CONTENTS
1 Technical data.................................................................................................1
2 Description......................................................................................................2
3 General information.......................................................................................3
3.1 Intended use...................................................................................................3
3.2 Warranty..........................................................................................................3
4 Basic safety information ...............................................................................4
4.1 Follow the instructions in the operating manual .......................................4
4.2 Warning ...........................................................................................................4
5 Supplied items................................................................................................5
6 Before first use...............................................................................................6
7 Handhabung / Messung................................................................................6
7.1 Calibration with the calibration block .........................................................7
7.2 Measuring procedure ................................................................................ 8-9
8 Cleaning and maintenance......................................................................... 10
9 Storage ......................................................................................................... 11
10 Service.......................................................................................................... 11
11 Disposal........................................................................................................ 12
12 Additional information................................................................................ 12
3 ORA_1GG-BA-d-1410
1Technische Daten
Mo d e l le
KE R N
Messbereich
und
S kalen
S kalen
teilung
Ge nauig k eit
Abmessungen
Produkt
Nettogewicht
O R A 1 G G
RI: 1,30
1,81
0,01 RI
130x20x30mm
0,400kg
Beispiel der Skala für den ORA 1 GG
2Gerätebeschreibung
1. Beleuchtungsöffnung mit Filter
2. Deckel
3. Polarisationsfilter
4. Prisma
5. Okular
6. Gehäuse
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3
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1. Technische Daten
Models
KERN
Measuring ran-
ge and Scales
Scale gradua-
tions Accuracy
Dimensions
Product
Net weight
ORA 1 GG 0,01 nD 130x20x30mm 0,400kg
Operating manual
Analogue refractometer
KERN & Sohn GmbH
KERN ORA 1 GG Analogue nD
Gemology/gemstones
Ziegelei 1
D-72336 Balingen
E-Mail: [e-mail]
Tel: +49-[0]7433-9933-0
Fax: +49-[0]7433-9933 -149
Internet: www.kern-sohn.com
GB 3. General information
3.1 Intended use
The refractometer is a measuring instrument for determining the refractive index
of gemstones. 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 is 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
2. Description
1. Illumination aperture with filter
2. Cap
3. Polarisation filter
4. Prism
5. Eyepiece
6. Housing
3 ORA_1GG-BA-d-1410
1Technische Daten
Mo d e l le
KE R N
Messbereich
und
S kalen
S kalen
teilung
Ge nauig k eit
Abmessungen
Produkt
Nettogewicht
O R A 1 G G
RI: 1,30
1,81
0,0 1 RI
130x20x30mm
0,400kg
Beispiel der Skala für den ORA 1 GG
2Gerätebeschreibung
1. Beleuchtungsöffnung mit Filter
2. Deckel
3. Polarisationsfilter
4. Prisma
5. Okular
6. Gehäuse
2
3
6
4
5
1
Version 1.1 05/2016
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 immediately.
Thoroughly clean the refractometer aer 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 refracto-
meter, as this could cause serious eye injuries
Do not touch the lenses with your fingers.
5. Supplied items
Aer 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
▸ Calibration block + Contact liquid (Diiodomethane)
6. Before first use
Remove the protective film (if present) from the prism surface [4].
7. Use/measurement
The refractometer can be used to quickly and accurately determine the refractive
index of gemstones. Please make sure your hands are dry before handling the
measuring device.
Some gemstones are monorefringent, they have only one refractive index. Other
gemstones - and actually the majority - have two different refractive indexes.
Birefringency is a measure of the difference between two refractive indexes in
bire-fringent gemstones and ranges between 0.003 and 0.287.
Only a very few gemstones are monorefringent – the only known gemstones
displaying this property are diamond, spinel and garnet.
The gemstone refractometer is small, lightweight and is frequently used in the
jewellery business.
ORA_1GG-BA-d-1410
KERN & Sohn GmbH
Ziegelei 1
D-72336 Balingen
E-Mail: [e-mail]
Tel: +49-[0]7433-9933-0
Fax: +49-[0]7433-9933-149
Internet: www.kern-sohn.com
Betriebsanleitung
Analoges Refraktometer
KERN ORA 1 GG Analog nD
Gemologie / Edelsteine
Version 1.0
12/2014
Example scale on ORA 1 GG
RI: 1,30-1,81 nD

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Important!
The ambient/room temperature and the sample temperature
influence the refractometer measuring result.
The scales are designed for an ambient temperature of +20 °C!
7.1 Calibration with the calibration block
Prior to any kind of measuring operation a calibration of the device has to be done.
Please put one drop of the contact liquid (Diiodomethane) on the prism [4]. Now put the
calibration block with the smooth and polished surface on the prism [4]. Use only slight
pressure. There must not be any pimples between the calibration block and the prism.
Close the prism cover [2].
Now please look into the eyepiece.
You should read 1,515at the light/dark boundary.
In case you read a different value the calibration of the refractometer has to be redone.
This recalibration can only be done in a dealers workshop.
After having finished please clean the refractometer. See point [8].
7.2 Measuring procedure
*
▸ Make sure your hands are dry before handling the refractometer.
Put the refractometer always on a flat table surface and do not tilt or hold it up with your
hands during the entire measuring process.
▸ Open the prism cover [2]and apply one drop only of the contact liquid*onto the
prism surface [4]. Now place the gemstone with as flat a face as possible onto the
prism [4]. There is now an oil film between the gemstone and the prism [4]. Close
the prism cover [2] and wait about 30 seconds (for optimal temperature equalisation
between the sample and device).
▸ View the measurement scale through the eyepiece [5]. Point the refractometer‘s
illumination aperture [1]at a bright light source while doing this (If the daylight
should not be sufficient, you can use an additional LED.
▸ Raise or lower the eyepiece [5]to focus the optics.
▸ Depending on the type of gemstone the light/dark boundary on the scale reveals
the result.
▸ To determine the birefringency index unscrew the polarisation filter [3]and place
it on the eyepiece [5]. Bring the light/dark boundary on the scale into focus by
rotating the polarisation filter [3]and read off the value. Now rotate the gemstone
by 90° and make a new measurement as described. Read off the second value.
▸ The difference between the first and the second value is the birefringency.
▸ For birefringent gemstones it is between 0.003 and 0.278. When the measure-
ments are complete screw the polarisation filter [3]back into its mount
on the cover [8].
▸ Carefully clean the supplied pipette [8]and the refractometer aer carrying out
the measurement.
Important!
Aer every measurement, use a lint-free, absorbent cloth to remove
the fluids from the prism surface [4]. Then carefully clean the prism
and prism cover using a cloth moistened with water or if necessary
alcohol, and dry both parts using a so, dry and lint-free cloth.
Avoid rubbing the prism [4].
!
8. Cleaning and maintenance
Clean the refractometer by using a so, lint-free cloth moistened with water, or if
necessary use pure 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 [4]with hard tools made from plastic, wood,
rubber, metal, glass etc. Hard objects can quickly damage the relatively so prism
glass, re-sulting in measurement errors.
The refractometer is maintenance-free.
Cleaning should be carried out immediately before and aer each use of the
refractometer 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
Aer 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.
!
*Further information on Measuring
The contact liquid (Diiodomethane), included with the standard outfit, has a
Refractive Index of 1.7425 nD.
If the gemstone to be tested has a Refractive Index, that is higher than 1.7425 nD,
another contact liquid (Anderson liquid), of which the Refractive Index is higher
than the Refractive Index of the gemstone, must be used.