Sample Thesis Paper
The aim of this experiment is to inspect the waveform of the ultrasound waves in a water tank and to estimate its speed in the water. The equipments that are used in the experiment are; a focused spherical transducer, a needle type hydrophone with in built amplifier, an oscilloscope (Tektronix TDS 1002B), Wavetek generator (module 193), thermometer and a tank filled with water.
The signal of the ultrasound is first electrically generated in the Wavetek generator, which transmits bourses of acoustic energy into the transducer crystal. The Wavetek generator is at the same time connected to the transducer and the oscilloscope. The transducer transforms this electrical signal into ultrasound waves that are proportional to their intensity and frequency. The oscilloscope also receives the electrical signal and displays it as voltage in time domain. The acoustic signal, which is send through the transducer, is received at the tip of the hydrophone needle, which is attached to a piece of piezoelectric crystal. A small amplifier is connected to the hydrophone to make its signal large enough to be easily visible on the oscilloscope. The oscilloscope also displays the amplified signal from the hydrophone in time domain. The screen then shows two traces, one for the transmitted signal, and another one for the received signal.
The transducer and the hydrophone are placed in the water tank. The transducer is positioned in a fixed holder on one side of the tank where else the hydrophone is positioned in a two directions movable holder, longitudinal and lateral, with a possibility of determining the position along these directions.