What is Beers Law?
August Beer was a German physicist who lived from 1825 to 1863. Beer’s specialty was optics. He developed the principle known as Beer’s Law, which explains how the intensity of a beam of light is reduced as it passes through different thicknesses of a medium. A simplified version of Beer’s Law that gives the OPTICAL THICKNESS of the atmosphere measured by a Sun photometer is the natural logarithm (ln) of the instrument’s EXTRATERRESTRIAL CONSTANT (Io) minus the ln of the intensity of sunlight measured by the instrument divided by the AIR MASS. (See the VHS-1 INSTRUCTIONS for the complete formula.
