KERN Analogue Refractometer ORA 1GG (Gemmology/Gemstones)
The KERN Analogue Refractometer ORA 1GG was specially developed for professional use in gemmology and gemstone testing. It enables precise determination of the refractive index of jewellery and gemstones. Compared to similar devices, this solution impresses with its high reliability, easy handling and robust design, which is optimised for continuous use in workshops and laboratories. Thanks to its finely graduated measuring range and durable mechanics, it is the first choice for jewellers, gemstone experts, goldsmiths, trainers and testing centres.
Precision, reliability and ease of use for gemstone analysis
With a wide measuring range from 1.30 to 1.81 nD, this handheld refractometer offers exceptionally precise analysis of a wide variety of gemstones - from classic diamonds, rubies and sapphires to numerous coloured gemstones and synthetic materials. The device features an accurate scale with a fine graduation of 0.010 nD. This guarantees differentiated measurement results for reliable identification and quality control.
Technical highlights at a glance
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Measuring range: 1.30 - 1.81 nD (refractive index for gemstones and jewellery)
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Division: 0.010 nD for optimum resolution when differentiating between similar materials
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Dimensions: 130 x 70 x 30 mm - compact and mobile, ideal for flexible use
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Gross weight: 810 g / Net weight: 718.16 g for stable handling
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Scale: Refractive index (nD), universal scaling with clearly legible values
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Adjustable eyepiece: Allows individual adjustments for different visual acuity requirements
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Accessories: Storage box, calibration solution, pipette, screwdriver, cleaning cloth; calibration block if required
Particularly noteworthy is the well-designed, maintenance-free construction. The device does not require any electronic components, making it particularly robust, durable and easy to maintain. The high-quality manufacture of the prisms and the optical system ensures that consistent and precise measurement results are always achieved, even with intensive use. Industry standards and certifications The model meets all standards applicable in gemstone analysis for accuracy and operational safety. As a manufacturer, KERN & SOHN is committed to consistent compliance with industry-relevant standards and certifications, including precision requirements in accordance with international and national standards for laboratory equipment and jewellery tools.
Identification of gemstones: Precise measurement of the refractive index for reliable identification and differentiation, e.g. between natural ruby, spinel or synthetic corundum.
Quality testing in workshops and laboratories: Routine testing of delivered gemstones, detection of counterfeits or material mixtures.
Production support: Inspection of raw materials in production, e.g. for selecting the most suitable stones for high-quality jewellery.
Education & training: Indispensable laboratory tool for jewellery and goldsmith schools to teach the practical use of measuring instruments in the classroom.
Demonstrations at trade fairs or seminars: Its compact design and ease of use make it ideal for mobile use.
Working with accessories and contact agents: Ideal for use with contact fluids and polishing agents, specifically for measuring transparent and translucent gemstones.
In use, the device typically encounters substances such as immersion fluids (e.g. monobromonaphthalene), special cleaning fluids for maintaining the prism surfaces, and various oils for contact measurement. These are essential for the reliable analysis of materials with difficult surfaces.
FAQ - Frequently asked questions
How is calibration performed?
Calibration is easily performed using the solution or calibration block supplied. Simply apply the calibration solution to the prism, close the device, focus with the eyepiece and adjust the scale precisely using a screwdriver.
Is the refractometer suitable for all gemstones?
Yes, the large measuring range covers the refractive indices of all common gemstones (diamond, sapphire, ruby, topaz, quartz, spinel, etc.) as well as many synthetic gemstones.
How often does recalibration need to be performed?
Regular calibration is recommended - especially before new measurement series, after trips to trade fairs or in the event of significant changes in the ambient temperature. This ensures consistent precision even under changing conditions.
Do I need special contact fluids?
For the measurement of many gemstones, the use of a suitable contact fluid is advisable, as this optimises light refraction and thus enables more accurate comparative measurements. Suitable substances are available commercially as an option.
Can I use the device without glasses?
The freely adjustable eyepiece allows quick adjustment to individual visual acuity. This means that even users with poor eyesight can work comfortably and accurately.
Conclusion
The analogue refractometer from KERN & SOHN is a professional and reliable solution for jewellers, gemstone experts and educational institutions. Its robust, maintenance-free design, combined with maximum measuring accuracy and practical accessories, ensures precise results in the laboratory, in the workshop and on the go. Anyone who values quality and flexibility in gemstone analysis will find this to be an optimally coordinated tool that impresses in all areas of modern gemmology.
