Noise and Interferences in Electrical Networks—An Undergraduate Experiment

The topic of noise and interferences in electrical networks is seldom discussed at the sophomore or junior levels. Electrical Engineering students, however, may encounter interference problems in their first laboratory course. Practical techniques of noise minimization in measurement setups are usually considered a work of art rather than a topic that can be methodically introduced. This paper describes a laboratory experiment investigating noise sources and their elimination that requires only inexpensive and generally available instrumentation. Background material is presented in a simplified manner taking into consideration the fact that the students at this level have not been exposed to probability and advanced electromagnetic theories. The experiment concentrates on the environmental noise and the various techniques to reduce the coupling between the system and noise sources. A brief introduction to noisy signal detection techniques is also included.