In this month's article we are going to explore an often overlooked sensor specification: amplitude linearity. Linearity, defined quite simply, is a numerical value that expresses how much a sensor's sensitivity changes with respect to the change in excitation amplitude. Linearity tests are commonly conducted for sensors with a relatively "low" sensitivity because these sensors generally experience more extreme measurement conditions. In the sound and vibration world, these are the sensors that are often used to capture high-energy events such as shock events for acceleration, and blast events for pressure. Due to the high variability in excitation that these sensors undergo, test and measurement engineers will often specify to continually quantify the performance of a sensor's linearity during its recalibration cycle to ensure consistent results...