Optical Activity

Optical Activity …design  a full range of polarimeters used in food, chemical and manufacturing laboratories worldwide.

Optical Activity - logo

Their polarimeters start with the new, low cost, compact AA65 polarimeter and go right to the PolAAR 3005 with 5 wavengths and 0.001 degree resolution.


Optical Activity were one of the first manufacturers to adopt digital signal processing and have frequently pioneered Polarimeter instrument design.

All of their polarimeters employ a unique operating principle patented by Optical Activity Limited in the 1970’s, that allows measurement of flowing samples and tolerates some turbulence, small bubbles or suspended solids, which completely upset other designs of polarimeters.

PolAAR features:

  • Manufactured using a substantial aluminium casting with tough aluminium cover – for rigidity and strength, and of course resistance to chemical attack.
  • All PolAAR versions are full circle polarimeters with a reading range of 90 angular degrees (in excess of 250 sugar degrees).
  • A tungsten halogen lamp produces a highly stable, white light source with a typical life in excess of 2000 hours; it is inexpensive and easy to replace by the user.
  • A very narrow-band interference filter is used to select wavelength; as the optical rotation of most samples is highly dependent on the wavelength.
  • The standard single 589.44nm wavelength is also suitable for dark samples, absorbing up to 99.9% of the incident light, equivalent to OD 3.0, without loss of accuracy.


Recently Optical Activity introduced Peltier ThermoTubes, and these with optical interference filtered light source and multi-wavength selection give amazing performance.






Index Instruments are a related company with a complete range of digital refractometers.

Follow links for more information
Optical Activity Products Optical Activity Technology
AA 65 – Low cost models Calibration plates for polarimetry
AA 10 – High Accuracy models ThermoTube leaflet
PolAAR – fully featured, highest accuracy Dextran and Sugar Purity Tester