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Refractometers with Electronic Temperature Control - TCR range

TCR 15-30 Refractometer

The TCR refractometer incorporates electronic temperature control using Peltier cell technology which has been developed by Index Instruments over the period since we first launched a model using Peltier cells in 1996. The TCR has a proven record for reliability and ease of use, both in factories and in laboratories throughout the world.


The TCR is exceptionally easy to use and has been specifically designed to be a robust instrument which anyone, with minimum training, can use to obtain rapid, accurate refractometer measurements of a large variety of samples. The instrument has a single touch-sensitive button on the top plate which the operator uses either to send an output to a PC or printer, or initiate a reading depending on how the TCR has been set to operate. The flat stainless steel top plate makes this instrument particularly easy to clean.

Versatility and Security

The TCR refractometer is also extremely versatile; the analysis parameters are set using an infra-red remote control unit. Having set the unit for a particular analysis, the remote control can then be removed from the working area to prevent, for example, unauthorised alteration of the parameters by production staff. The TCR is therefore ideal for repetitive quality control of a particular type of sample.



Once the scale has been selected (RI, Brix, temperature corrected Brix, etc.), the sample control temperature set, and the sample stabilisation parameters chosen using the remote control, all the operator has to do is apply a few drops of sample, or a small amount if a paste, to the prism and close the cover.

The display panel provides a large clear digits giving the results on an LCD screen. The back-lit display is easy to read in bright light conditions and with a read time of less than 3 seconds, the sample reading is always up-to-date. In continuous mode, the result is displayed instantaneously when the hinge cover is closed. For samples which need time to reach a stable temperature, you can set a delay time from 3 to 999 seconds. As each measurement is made, the result along with scale, time and date is automatically output to a printer or PC if attached to the unit. Alternatively, the TCR can be set to automatically determine when the sample has stabilized and only then display or output the result.

PC Software is available from Index Instruments Ltd. to connect your TCR to data storage, spread sheets or documents on your computer.

Temperature Control

The sapphire prism and surrounding metal are controlled from below using a Peltier cell. Fan cooling is not required and the TCR has no moving parts. The sample cover is extremely well insulated, and once the cover is closed, the small sample volume quickly stabilizes at the control temperature. The most frequently used temperatures in refractometry are 20°C and 25°C and the TCR easily controls at these temperatures to within 0.03°C under normal comfortable ambient working conditions. The TCR can also operate up to a maximum set temperature of 40°C. If you have samples which need to be measured at higher temperatures, it becomes necessary to control the temperature of the cover as well as the prism and so the TCR is not suitable; consider instead the Index Instruments GPR 12-70E which provides electronic temperature control to both prism and cover up to 100°C or the GPR 12-70 or GPR 12-70X which use flowing fluid to control both prism and cover and can operate up to 70°C.


The TCR is a “critical angle refractometer, working by reflecting light from the interface between the sapphire prism and the sample. Even dark and difficult samples such as molasses, coffee, sauce and dairy products can be measured with the same ease and accuracy as clear samples. Alternative sample cells are available for automatic or semi-automatic sampling. Contact Index Instruments for advice.


With only a small 'footprint' of less than 24 cm x 24 cm the TCR makes little demand on laboratory working space. Mini-printers are available amongst optional accessories.


The TCR can be supplied, on request, with a UKAS (United Kingdom Accreditation Service) certificate of calibration. Liquid standard samples with UKAS Calibration Certificates are also available for your own calibration checks.

The TCR 15-30 has an internationally recognised IP67 rating for physical impact protection and water resistance and and is manufactured to comply with the European Directives on Electro-Magnetic Compatibility, carrying the internationally recognised CE mark.

Technical Specifications Download Brochure
  • Accurate temperature control
  • Wide range: RI - 1.32 to 1.53,
                            Brix - 0 to 95%
  • Resolution 0.00001 RI, 0.01 Brix
  • Temperature range 15°C to 40°C
  • Multi-scale models
  • No function keys, parameter changes via hand held remote control unit
  • Totally waterproof to IP67 standard
  • Simple to use

Application Notes

» Dairy Products
» Measurements of Fruit Juices
» Official Methods List for Refractometers
» Sorbitol (D-Glucitol) in Water

Index Instruments USA

Tel: +44 (0)1487 814313 Fax: +44 (0)1487 812789
Index Instruments Ltd. Bury Road Industrial Estate, Old Station Road,
RAMSEY, Huntingdon, Cambridgeshire, PE26 1NF, England

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