Wireless Polarimeter

The Wireless Polarimeter has both Bluetooth^® and USB connectivity, making it possible to analyze chiral compounds with your iPad^®, Chromebook™, Android tablet, or computer. It is ideal for introductory experiments in Organic and Biochemistry, where chiral compounds are of special interest.

PASCO’s Wireless Polarimeter passes plane polarized light through a vertical sample, which contains a chiral compound, followed by an analyzer and detector. The optical rotation is determined by finding the angle between the starting position and the location where the optimum light level transmits through the cross polarizer.  Students can use the rotation data to calculate the concentration of a chiral sample, while the specific rotation (amount turned per g/ml dissolved) is an intrinsic property that can be used to differentiate molecules or determine racemic mixtures.

How It Works

The speed of light around chiral atom centers is anisotropic (slower for light vibrating in one dimension than that at 90 degrees).  This causes a component of the oscillation, say the horizontal portion, to slow down causing the composite plane of oscillation to rotate as it passes through the solution.  A second polarizing film is rotated until a maximum amount of light makes it through to the detector.  The angle from initial orientation to where it was deflected is considered the optical rotation. A single color of light is used because much like red light refracts less than violet through a prism, in an optically active solution, red is rotated less than orange, less than green, then blue and violet.  This can be observed in the polarizer demo set (OS-9477A) as a solution of Karo syrup changes color between the two larger polarizers from red to violet as the cross polarizer is rotates to let the next color through the appropriately aligned color.