Loss of a Laser

Aim: To construct and manufacture an ultrasonic rangefinder following a basic design to gain experience in the following techniques: circuit manufacture, soldering, trouble shooting and calibration.

Abstract: This project required an open approach to construct an ultrasonic rangefinder from beginning with the circuit board design, thereafter populating with components to finally achieve a working device. The device to be tested at every stage of manufacture until completion where it was then calibrated and fine-tuned to be able to measure a distance between itself and a large plane a distance away from it through the relationship between voltage and distance. Using the device it was found it operated in the region of 0.7m to 3.2m and out with this range the device failed. Analysing all the results from the experiments conducted found the device was accurate to measure 0.3milimetres, per metre, this valued was deduced by the RMS value of the residual plot.

Introduction: The principle of the ultrasonic rangefinder is to measure a range of distances using ultrasonic sound waves. The term ultrasonic waves means a signal that transmits signals at a high frequency, one which is over the frequency of 20 kHz; this is the upper range of human hearing which is in the range of 20Hz to 20 kHz (Freedman, 2008). Being so high in frequency and unnoticed by the human ear is ideal as it can have many applications in industry, healthcare and everyday life. In industry ultrasound is regularly used as a means of non-destructive testing to monitor the thickness of materials and check for flaws within the material on production lines without the need to damage or open the material itself, this proves as an effective way to measure important aspects with minimum disturbance to the production line (J. Krautkrämer, 1990). Undoubtedly the biggest use for ultrasound is in healthcare, the range of treatments which utilises ultrasound is vast. A few examples of its uses in healthcare would be; the use of ultrasound when administering chemotherapy as it agitates the tissue