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Schmidt + Haensch | Refractometers

Refractometry – refractive index and more

In a vacuum, light travels at 300.000 km/s while travelling through water, the speed is about 225.000 km/s, which is 25 % less. In a sapphire it will only reach 170.000 km/s.
A refractometer is a measuring instrument for the speed of light. The result will not be indicated directly but related to the speed of light in air. This comparison is called refractive index. The indication, that a certain material has a refractive index of 1.5 thus means, that the speed of light travels 50 % faster through air than through this material.

Who is interested in the speed of light in samples?
The refractive index is a value specific to a material. It depends on temperature and wavelength (colour) of the light. Thus using a refractometer, will enable you to determine the concentration of a material, if temperature and wavelength are known. But it is also possible, that different materials have the same refractive index at various concentrations. Thus a clear determination of liquid substances may only be successful with binary mixtures (Mixtures consisting of two compounds).

In practice, the refractive index determines the mixing ratio also of multicompound solutions quite exactly and easily as in general only the concentration of one of the componends needs to be determined. Thus it is a quantitative measurement. With known compounds, also quality may be determined. For mixtures like for example olive oil or orange juice, the measuring value within a certain range corresponds to a certain quality.

Thus refractometry is a quality control of substances.

There is a definite correlation between the refractive index and the composition of many two-compound solutions. The best known example for such a mixture is a solution of sucrose in water, which has been studied throughly. A refractometer can be grated in a way that the value may be indicated directly as dry substance % RTS. For sucrose, this unit is also named Brix (abb. Bx).

The determination of the density of samples can also be done with refractometry. As a rule in optical measuments density and dry substance corresponds to each other.

Refractometers convert the measured refractive indices in concentration or density.


VariRef Series

VariRef the New Laboratory Refractometer

The VariRef combines proven S&H technology with the modularity of the VariFamily.
The new double isolated Peltier systems allows fastest temperature control and reduces the influence of environment temperature, resulting in fast and precise measurements.
The VariRef has the well-established S&H sample room. Its flat shape is ideal for easy cleaning. When dealing with hard to clean or hazardous materials we offer you a special covered version to ensure a long and proper product life.
The LED light source and the self-checking capabilities for cleanliness, environment temperature effects, calibration and more result in a virtually maintenance free product life.
To ensure highest precision over the long product life, the VariRef enables you to make a multi-point calibration for the complete measurement range. Thus giving you the tools for a fast and economic maintenance at your side.
With the VariRef you have access to the complete scale library of Schmidt + Haensch offering readymade solutions for numerous applications.

  • Modularity
  • Fastest temperature control
  • Flat sample room, easy to clean
  • LED light source
  • Virtually maintenance free

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    ATR P Touch

    ATR-P Touch

  • High-performance refractometer
  • Rugged measuring head (IP65)
  • Single or flow through measurements
  • For permanent use in production laboratories
  • Combination with polarimeter (Purity Analyser)

  • The critical angle refractometer ATR-P is especially designed for applications in the sugar industry. Complete system consists of the ATR-P measuring head and the “L-Controller” electronic unit. As an alternative to the “L-Controller” electronic unit, the ATR-P measuring head can be connected to a PC or laptop. In the minimal version configuration and calibration are performed using a supplied free software. Much more comfortable version is the PC software “Aquisys Basic”.

    Main Features:
  • High-performance robust Refractometer for the determination of mixing ratios (mass percent)
  • Quality and quantity control of liquids, especially for sucrose solutions
  • Highly accurate and reproducible measuring results in no time at all
  • Electronic unit separated from the measuring head
  • Very robust and waterproof (IP65) measuring head made from stainless steel
  • Single or flow-through measurement
  • Various sample room covers / flow through doors optionally available
  • Temperature correction of samples via external water bath – rapid temperature correction even larger sample volumes
  • Temperature compensation of Brix scale
  • Easy to calibrate with sucrose solutions
  • Measuring head can be connected to the PC and operated as stand-alone device
  • User friendly Operation System displayed by a high resolution 7″ TFT Touchscreen
  • Documentation according to GLP/GMP
  • Energy saving LED light source

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    ATR BR


    Compact laboratory refractometer for versatile applications

  • Robust refractometer
  • Very stable measurements
  • For versatile applications
  • Easy handling
  • Excellent price-performance ratio
  • 0.3 ml sample volume is sufficient

  • Compact laboratory refractometer.
    The new ATR-BR is an critical angle refractometer for the measuring of liquid media from low to high viscosity, and independent of opacity and color. The ATR instrument are available in a variety of configurations for laboratory and production quality control.

    The newly designed casing offers more space for a bigger LCD display and a splash proofed foil keyboard. Batch numbers can be entered directly and also simple form may be created and printed out.

    4 special scales, one of them being programmed as Brix scale by the factory, allow various applications in production and laboratory.
    The software of the ATR-BR, designed close to the practice, makes it possible to take the mean value and to determine standard derivation and adjustable measuring delay for special measurement in dependence of the temperature. All functions may also be controlled via PC using the remote control program.

  • Chemical industry: Solvents, organic polymers, distilled products, solutions of inorganic compounds
  • Food industry: Yoghurt, jam, fruit extract, syrup, honey, coffee extract, vegetable fat, albumen, chocolate, milk, baby food etc.
  • Beverage: Soft drinks, fruit juice, wine, beer
  • Medical applications: Serum, blood, urine
  • Pharmaceutical/cosmetical industry: Essences, essential oils, flavors
  • Petrochemicals: Oils, fats, waxes, naphthalene’s, raw oils, varnishes, paints

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    ATR L


    Digital multiple wavelength refractometer

  • High-precision refractometer
  • Automatic dispersion measurement
  • Seven wavelengths fixed
  • Automatic ABBE number measurement
  • Ideal for research and development

  • The digital, fully automatic spectral refractometer ATR-L consists of an electronic unit separated from the stainless steel measuring unit. Dispersion measurement at 7 wavelengths over the full visible range. A sample volume of 0,3 ml is sufficient for measuring. The refractometer is equipped with a Peltier thermostat (no external water bath necessary). Refractometers are widely used in food, oil, fuel,.. to measure the concentration of components. They measure the critical angle of total reflection and calculate the refractive index from this value. The refractive index of a substance depends on the wavelength of light and usually increases towards shorter wavelengths. The ATR-L is used for a better characterization of this behavior (dispersion) which could give a fingerprint about the material itself. This makes it possible to distinguish substances which otherwise are similar at 589 nm (sodium- wavelength).

  • Research and development labs, where the exact knowledge of material properties is of great importance.
  • Medical research (plastic lenses, contact lenses)
  • Optical communication technology (polymer materials, special optical liquids, glasses and glues)
  • Fingerprinting characterization of high-quality products like wine, perfumes, alcoholic beverages, etc

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    DHR 95

    DHR 95

    Digital handheld refractometer – Brixmeter

  • Perfect refractometer for field analysis
  • Application specific scales
  • 5-digit, full view LCD screen
  • Results displayed in 2 seconds

  • Measurement of liquid media from low to high viscosity.
    Handy design, simple operation, reliable.
    Automatic temperature compensated Brix value within +5 to 70 °C.
    Various models are available and more specific for honey, wine, saline or glycol.

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    Visual Handheld

    HR Visual Handheld Refractometer

  • Perfect refractometer for field analysis
  • Easy handling
  • Different models available

  • Handheld refractometers are classic, visual refractometers and are used for the determination of the refractive index of liquid media of low or high viscosity. They are mainly used for quick on-the-spot-control of process streams and the field analysis in fruit and vegetable plantations. Different models of handheld refractometers for special application available.

    Determination of:
    • % Brix (4 different measuring ranges available), % Oechsle
    • Urine determination (0 – 12 g/l)
    • Salinity tests (0 – 28 %)
    • Wine measurements (0 – 32 % Brix; 0 – 140°Oe)
    Resolution and precision depends on the model.

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    ABBE-Refractometer AR12

    ABBE-Refractometer AR12

  • Broad measuring range
  • Simple handling
  • Small sample volume needed
  • Water bath lockable
  • Ideal for school/education

  • The Schmidt+Haensch ABBE refractometer AR12 is a classical, visual refractometer, named after its inventor Ernst Abbé and designed for the determination of the refractive index of liquid media with high or low viscosity. It is used in the fast control of liquids and the "in-field analysis".

    The ABBE refractometer AR12 is equipped with hose connections at the prism unit for the thermostatisation of the optical parts. The temperature is measured with a digital thermometer. The measuring principle is based on the law of Snellius (law of refractive index) and is able to measure with transmitted or totally reflected light. With a contact fluid even solids can be measured with the ABBE refractometer.

    Optional an illumination unit is available for prism and scale illumination with a red LED.

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    In-Line Process Refractometers

    Inline Process Refractometers measure the refractive index continuously and in real time, thus determining the concentration of liquids or the mixing ratios of binary or quasi-binary mass ratios. The measurement is independent of turbidity, color, absorption and viscosity, which ensures maximum precision and better process control.

    Process refractometers can be installed in pipelines, mixing tanks, reaction boilers, storage vessels, cooking appliances or evaporators using various flange connections.

    Find more information on the following Schmidt-Heinsch webpage

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  • Digital thermometer (AR12)
  • ATR sample room cover
  • Stainless steel sample cover for single measurements with Schmidt +Haensch refractometers of the ATR series
  • ATR flow through compartment door:
  • Stainless steel flow through compartment door (sample room volume approx. 80 μl) for laboratory refractometers of the ATR series from SCHMIDT + HAENSCH.

    Calibration Standards for Refractometer at 589nm in 10ml glass bottles
    Substance Refractive index Temperature range Certificate Tolerance of RI
    De-ionised water 20°C ≈ 1.333 20°C and 25°C factory certificate dnD=0.00005
    De-ionised water 20°C ≈ 1.333 5 to 95°C factory certificate dnD=0.00005
    Silicon Oil 20°C ≈ 1.404 20°C and 25°C factory certificate dnD=0.00005
    Silicon Oil 20°C ≈ 1.404 5 to 95°C PTB certificate at 20°C dnD=0.00001
    other temperature
    Paraffin Oil 20°C ≈ 1.446 20°C and 25°C factory certificate dnD=0.00005
    Paraffin Oil 20°C ≈ 1.446 5 to 95°C PTB certificate at 20°C dnD=0.00001
    other temperature
    Technical White Oil 20°C ≈ 1.474 20°C and 25°C factory certificate dnD=0.00005
    Technical White Oil 20°C ≈ 1.474 5 to 95°C PTB certificate at 20°C dnD=0.00001
    other temperature
    CRM-R Custom 10 ml factory certified reference material, customer specified RI in the range 1.36 bis 1.70 RI, calibrated to dn=0.00005 accuracy

    Certified Reference Material (CRM) Sugar
    CRM-R Saccharose B Sugar reference solution, different concentrations, separate containers for saccharose and distilled water, after shuffle one week durable (concentration range: 0 - 55 Bx --> please specify desired concentration when ordering)
    CRM-R Saccharose P Sugar reference solution, different concentrations, separate containers for saccharose and distilled water, after shuffle one week durable (concentration range: 0 - 55 Bx --> please specify desired concentration when ordering), with factory certificate

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