3.3 Instrumentation

In recent years, as micro machine-work and measuring technologies advance, a large number of instrumentation which is applicable to centrifuge model tests is developing. Wide variety of instrumentation is employed in centrifuge model tests by universities and research institutions. As transducers such as earth pressure transducers and accelerometers are buried in the model ground, the transducers should be small and light enough to avoid affecting the test result. In addition, the structure of transducers is required to endure the self-weight in a centrifugal acceleration field and resolution and gain should be sufficiently high. When selecting instruments, it is necessary to choose carefully types, shapes, dimensions and gains which meet the test purpose. The instruments should be tested and calibrated over their working load using the model ground, which is performed in a centrifuge or at the Earth's gravity.

This chapter introduces major instruments which measures displacements, stresses, pore water pressures, and accelerations in centrifuge model tests. Also illustrated are the data acquisition system, the image processing system and the fluid control system.