Pressure Sensors and Filtering Techniques for Stone Stability Assessment

Abstract

This report is structured as follows: In chapter 2 the importance of wall pressures with respect to the present research is described. The literature on wall pressures that was used, and some general features of wall pressure fluctuations are subsequently described in chapter 3. Chapter 4 deals with the pressure sensors. It begins with a brief description of some general features of pressure sensors. Then the criteria for the required pressure sensor are given. This is followed by a description of the two types of pressure sensors, which were acquired from commercial companies. The character of the noise that is present in the measured pressure signal is described in chapter 5. This chapter ends with a list that comprises numerous possible sources of noise. A few dedicated filtering techniques that can be used to attenuate the vibrational and acoustical noise are described in the next chapter (chapter 6). Several experiments were executed in order to get a further idea of the possibilities of the sensors, and the nature of the noise that will be present in the measured signal. The set-up of these experiments is described in chapter 7. An analysis of the tests that were executed is given in chapter 8. In this chapter the nature and magnitude of the various sources of noise are described. Chapter 9 presents the conclusions of the report. Based on these conclusions the requirements for the experimental facilities that are needed for the final experiments, and the choice of the best suited pressure sensor are given. MOST RELEVANT CONCLUSIONS - The pressure sensors seem to work satisfactorily regarding the accuracy and the frequency range they can cover. - Of the two types of pressure sensors tested, the Honeywell sensors are found to be more precise, as their range is better suited for the present application. - The temperature of the water must be kept constant, as the Honeywell sensor is influenced by it.