Development and modification of National Instruments Data Acquisition hardware for use in the centrifuge environment

This paper details the modification of a commercial data acquisition system for use in a geotech-nical centrifuge. As with many ‘off-the-shelf’ components put into service within the harsh high stress centri-fuge environment, they are not originally conceived to operate under these extreme conditions and thus it is not uncommon for high failure rates to occur in standard hardware items. In many cases successful modification can be implemented to strengthen standard components to enhance their robustness and operation. In this re-spect, this paper reports on difficulties experienced in the operation of a National Instruments PXI chassis sys-tem and its failure in the high gravity environment. Specific problems identified relate to fragility of the cooling fan systems that generate fault conditions that trigger auto shut down sequence of the chassis. A bespoke solution is developed and documented that has been successfully implemented to circumnavigate and mitigate fan failures

Centrifuge Health Monitoring of the 50gTon beam centrifuge at the University of Sheffield

In order to fully understand scientific test data it is crucial that we first understand the back-ground centrifuge operational environment and its variation with time and centrifugal acceleration. For exam-ple, changes in ambient air temperature or relative humidity in the centrifuge chamber during operation can have a significant impact on the evaporation levels of water from the surface of a clay model. It is vital to un-derstand these temporal changes in order to mitigate drying out of the soil surface as this would have a detrimental impact on model performance. This paper details the development of a centrifuge health monitoring system capable of measuring environmental parameters over natural seasonal variations of the laboratory environment but also during test conditions. The results of a series of preliminary tests of different duration, acceleration and configuration are discussed to demonstrate the significant changes that occur in the scientific environment during operation