The instrument we show here is designed to be modular, with increasing complexity (and cost) enabling more types of measurements. A summary of the required and optional hardware, their purpose, and approximate cost can be found in Table . The most basic setup requires a computer, a pulser, an ultrasonic transducer, and an oscilloscope. The pulser generates a high voltage, short duration pulse which is fed to a piezoelectric transducer, generating the ultrasonic wave. After interacting with the sample, the wave is then picked up by the same transducer (pulse-echo mode) or a different one (transmission or pitch-catch) and the resulting voltage signal measured by an oscilloscope. This process is repeated and the results averaged to produce the measurement reported on the computer. The connection of the hardware components determines what kind of measurement is performed -examples of basic transmission and pulse-echo measurements are shown in Figures and, respectively.