What is absorbance in optical measurements?

Absorbance in optical measurements refers specifically to the amount of light that a material absorbs when light passes through it. This concept is central to understanding how substances interact with light, particularly in applications involving spectroscopy. When light encounters a material, a portion of that light can either be transmitted, reflected, or absorbed.

The measurement of absorbance is important because it allows for the quantification of how well a particular substance can absorb light at specific wavelengths, which can be indicative of the concentration of a substance in a solution or its specific properties. High absorbance values indicate that a significant amount of light has been absorbed and therefore less is transmitted, which is key in many analytical chemistry techniques.