In this book, viscosity is measured using a standard rotational viscometer and an acoustic emission (AE) viscometer. Typically, current viscometers need more time before measurements are taken. However, with the AE viscometer, the time targeted should be shorter. The factors that are being studied are the thickness of the fluid, spindle speed, duration of time taken, and the position of the spindle. A two-level factorial design is used to design the experiment, and the design of the experiment (DOE) is used to analyze the data to find the most significant factor.