Although piezoelectric materials are often used as actuators in order to make small precise movements, it can be difficult to measure these displacements in an industrial environment. Consequently simpler methods have been sought to measure the piezoelectric activity, such as resonance methods, and measurements of the piezoelectric coefficient d33 using the direct method (often called the Berlincourt method).This good practice guide will examine the advantages and disadvantages of the method in detail and with some experimental validation using typical PZT ceramics examine the validity of using the data from this method to predict the displacement of materials in real conditions.