ABSTRACT
All measurements are to some extent exposed to disturbances and this is particularly the case in electrophysiological measurements because the signal amplitude is low compared to the disturbances. The disturbances have different origins; some are generated in the environment, some arise as a result of the experimental conditions, and others such as noise are inherently generated in the measurement system. To reduce the disturbances to acceptable levels can be difficult and requires well-designed equipment and a qualified measurement engineer to plan the measurement system and also to carry out or survey the measurements.
