The Abbe Refractometer derives its name from the 19th Century physicist Ernst Abbe (1840-1905). Abbe designed an instrument for measuring the dispersion of light and this became the precursor for the so-called ‘Abbe Refractometer’.
Abbe refractometers have been manufactured by Bellingham + Stanley since the company was founded in 1915 and even to this day, research scientists & academics across the globe turn to Abbe 60 series of refractometers when looking for the ultimate in refractive index measurement performance.
Abbe 60 series refractometers achieve high performance by eliminating optical and human factors that that limit direct reading Abbe refractometers, enabling Abbe 60 Series refractometers to offer 5 decimal place refractive index results across the whole scale.
Abbe 60 refractometers are still used to this day for dispersion measurement within the manufacture of contact lens substrates, polymer films, fibre optic and liquid crystal evaluation but the use of Abbe refractometers within the food and industrial processing sectors has somewhat demised since the introduction of the digital refractometer back in 1980. However, Abbe 60 high accuracy refractometers still play an important role within scientific research, academia and in specialist manufacturing processes, especially where high accuracy refractive index measurement is required at narrow bandwidths, such as those emitted by lasers or spectral arc lamps.
With good temperature control using an external waterbath and by way of a micrometer drum that eliminates guess work where the borderline falls between graticule lines on the scale, an average accuracy of ±0.00004 RI can be achieved across the specified measuring range from the linear 0-60 refractive angle scale.
Abbe 60 refractometers have the capability of measuring not only with transmitted light (transmission mode) where sample passes through the sample but is also capable of measuring using a reflected ray (reflection mode), where sample is reflected off the sample surface. The reflection mode is particularly useful when measuring non-homogenous samples, semi solids or even solids such as rubber and polymers.
High Accuracy Abbe 60 Refractometers are ideal for use in research and development, quality control and other industrial laboratories where the highest accuracy and precision is often sought. The Abbe 60/ED conforms to the requirements of ASTM D1218 and is used widely throughout the petroleum industry. The Abbe 60/LR offers low range RI measurement of anesthetics.
Abbe 60 Series refractometers can also be used to determine the refractive index of pure liquids, solutions and formulated products including: flavourings, fragrances, oils and fats, solvents, plastics, resins, adhesives and many other industrial chemicals but many of these industries have now turned to high accuracy digital instruments that can achieve similar results at the touch of a button.
The instruments come complete with digital thermometer, traceable standardization plate, contact liquid, power supply, and instructions for use. Simple software is available for converting refractive index, Brix, and dispersion etc.
Sodium Lamp Outfit
The sodium discharge tube is housed in a height adjustable enclosure mounted horizontally to the lamp outfit base. Sodium bulbs are ideal for regular use as they are relatively inexpensive to purchase and have a working life in excess of 3,000 hours.
Spectral Lamp Outfit
The Spectral Lamp Outfit can be used in conjunction with a number of optional bulbs including mercury, cadmium and helium versions to provide well defined narrow bandwidth spectral lines. The bulb is mounted cap down in the metal shroud, which slides on a vertical post for height adjustment. Spectral bulbs are complex items manufactured specifically for scientific purposes and are both expensive to purchase are short in working life (approx. 200-hours). Interference Filters or software may be used to define specific spectral lines emitted from the bulbs.