Introduction This document provides an introduction to the quartz crystal microbalance (QCM) which is an instrument that allows a user to monitor small mass changes on an electrode. The reader is directed to the numerous reviews1 and book chapters2 for a more in-depth description concerning the theory and application of the QCM. A basic understanding of electrical components and concepts is assumed. The two major points of this document are: ? Explanation of the Piezoelectric Effect ? Equivalent Circuit Models |