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The Instruments Used to Measure the Optical Rotatory Dispersion

Optical rotatory dispersion (ORD) is a scientific principle defined as the variation in the optical rotation of a substance with a change in the wavelength of light that passes through it. ORD has many scientific applications that require certain scientific equipment in order to be studied and manipulated.

Polarimeter
- Polarimeters are one of the primary instruments used in ORD. They are used to measure the angle of rotation of polarized light that is passed through a substance. Polarimeters are very sensitive and delicate instruments that consist of a fixed prism called a polarizer and a movable prism called an analyzer. Monochromatic (single-color) light is shone through the polarizer onto the substance being studied. The light is then rotated and examined with the analyzer to determine the angle of rotation.
Spectrophotometer
- An even more advanced form of technology used in ORD is the spectrophotometer. The spectrophotometer is used to measure the intensity of a beam of light as a function of the light's wavelength. It is an incredibly sensitive device that can measure beams that are only nanometers (billionths of a meter) long.
More About ORD
- ORD is used in a number of scientific and industrial areas. One in particular is the sugar processing industry. Sucrose, the chemical name for the white sugar you used in many different foods, is one of the substances that has the special properties required for ORD. During the refining process, ORD is used to examine sucrose molecules in sugar cane syrup to ensure that sugar crystals are separated properly. ORD is also used in mineral studies and medicine.

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