A calibration curve is a mathematical tool used in analytical chemistry that provides a set of reference points that unknown chemical substances can be compared to. When analyzing certain substances, scientists are often unable to get a completely accurate understanding of the substance's makeup. With a calibration curve, chemists can compare known information about unknown substances to make estimates about its makeup and chemical properties
Calibrations curves are usually constructed using standard samples of known chemical substances, according to the University of Maryland. By separating these chemical compositions with a solvent and analyzing them by exposing them to other known chemical agents, scientists can learn specific details and properties about each unique substance. These properties are then recorded and represented graphically. There are a number of different advanced equations that can be used to develop calibration curves for various experimental purposes.
When a laboratory is dealing with a substance of an unknown chemical composition, it can perform similar tests on the substances. By drawing comparisons between the information from the unknown substances and the information on the calibration curves, an estimate can be made about the composition of the unknown chemical. The estimates made by using calibration curves are relative and not absolute. However, these tests can be repeated and averaged over a number of experimental trials.