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ATM X2 Colorimeter

Designed specifically for sugar colour measurements
Conforms to a number of the latest I.CU.M.S.A. official methods including
GS1/3-7, GS2/3-9, GS2/3-10, GS2/3-18 and GS9/1/2/3-8
Highest accuracy for white sugars
Longest path length 163 mm

The measurement and monitoring of sugar colour that can vary from bright white to shades of yellow brown is an important function for the laboratories in sugar refineries and raw sugar mills, as well as the users of refined sugar products such as the food and drink industry, distilleries etc., the world over.

I.C.U.M.S.A., the International Commission for Uniform Methods of Sugar Analysis, has defined the scale for colour grading of white sugars that covers a range from 0 to 6, whereas 0 corresponds to a sugar of maximum whiteness, while 6 indicates a highly coloured low grade white sugar. The scale is based on colour type standards which are prepared from artificially coloured sugar.

The ATM X2 Colorimeter is an instrument dedicated to this important quality control function and has been designed to make the measurement, calculation and recording of sugar colour as easy as possible. Accuracy is improved by having fixed wavelength, very narrow bandwidth filters to select the measuring wavelength. The highest accuracy for White Sugars is achieved by using the longest path length cell of 163mm.

Dark Sugars can also be measured simply, quickly and accurately using a set of shorter path length cells which are recommended by I.C.U.M.S.A. These cells fit directly into the ATM X2 Colorimeter without the need for a special cell holder or adapter.

I.C.U.M.S.A. - Method GS2/3-18

I.C.U.M.S.A. Method GS2/3 -18 - The Determination of the Turbidity of White Sugar Solutions, recommend the use of 420nm as the wavelength for colour measurements of white and light coloured products, and a wavelength of 560nm for darker sugars. One version of the ATM X2 Colorimeter measures at both 420nm or 560nm with one key to select the wavelength required and then displays the absorption and the result in I.U. (ICUMSA Colour Units) at the wavelength selected.

Bottlers Method

This is the method for colour determination commonly used in the soft drinks industry. Another version of the ATM X2 Colorimeter offers simultaneous measurement at 420nm and 720nm as specified by the 'Bottlers Method' and displays the absorption reading at both wavelengths along with the calculated result in RBU (Reference Basis Colour Units).

All displayed results can be output to a printer or PC via the ATM Colorimeter's RS232 output port.

ATM X2 Colorimeter capabilities

Calculated ICUMSA Colour Units or RBU's depend on the cell length and the Brix of the sample. Pre-set cell lengths can be scrolled using built in keys on the basic ATM X2. Deviations from the standard 50 Brix concentration of the solution can also be scrolled, ensuring correct calculations whatever the sample.
However, the system can be extended further by use of a keyboard/interface unit allowing the date and time of every reading to be added to the output together with a short message to identify each result. The operator can also use the keyboard to select the required wavelength, type in the cell length and the Brix of the sample, ensuring accurate calculation and recording of all readings. The keyboard can be purchased as an additional accessory and is suitable for all three versions of the ATM X2 Colorimeters.

It is also possible to further automate the readings by connecting a refractometer to the RS232 port. Contact us for further details.

The ATM X2 is a compact colorimeter, and having no moving parts makes the unit extremely reliable. The lamp life is typically in excess of 2,000 hours, and is easy to change upon failure.

One of the main features of these instruments is their capability to accept long path length cells (up to 163mm) for the highest accuracy when measuring white sugar. Long glass cells are easily cracked or broken and therefore, we have designed a 163mm long stainless steel cell specially for these instruments. The cell has been constructed 20mm wide with a wider top for easier filling, handling and cleaning.

The shorter glass cells are also specially designed for the ATM X2, 20mm wide with thick walls to simplify filling and cleaning and to resist breakage or damage.

Technical Specifications Download Brochure

Three models available

  • ATM X2-420 single wavelength model operating at wavelength 420 nm – the wavelength specified by ICUMSA for official white  and light coloured sugar colour determination.  Displays absorption and IU (ICUMSA Colour Units)

  • ATM X2-420/560 dual wavelength model operating at wavelengths 420 nm and 560 nm – suitable for measuring darker sugars

  • ATM X2-420/720 560 dual wavelength model operating at wavelengths 420 nm and 720 nm, suitable for the “Bottlers Method” commonly used in the soft drinks industry.  Displays absorption and RBU (Reference Basis Colour Units)

(If you are interested in any other specific wavelength, please contact us)



Check the calibration of your ATM using one of our solid coloured glass test pieces supplied with a manufacturer’s certificate of calibration. These test pieces check the colorimeter reading in approximately the middle of the range at 420 nm.

Long sample cells are all made from high grade stainless steel for robustness.

Available in a choice of lengths;

163mm for the highest accuracy when measuring white sugars, or 100mm, the standard length in some industries.

Shorter cells are made from glass and are available as standard in lengths 10mm, 20mm or 50mm.


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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