CALIBRATION GRAPH (noun)

 

A graph that is used to determine an unknown value. Example: in a colorimetry experiment, a chemist would prepare, say, 5 solutions of aqueous Cu(SO4)2, each with a different concentration, and then scan each sample with a colorimeter to determine the absorbance of each sample. The chemist would then plot a graph of absorbance vs. concentration. This is the calibration graph. The chemist could then scan the absorbance of a sample of Cu(SO4)2 of unknown concentration, and from the reading and the calibration graph, determine its concentration.