Students' simple method for determining the parameters of an AC signal

The paper sets aside details of instrumentality to reveal the nature of the problem addressed by measurement. Its title is based on the title of a 1894 paper by Prof. W.E. Ayrton and his student H.C. Haycraft. They described a new and simplified method of measurement to improve the teaching of their underlying topic, and that is the goal of this paper. In the work described here, the measurand is taken to be an equation representing an alternating signal, and the declared values of the measurement are estimates of the parameters of the equation. It is shown that the parameters of the ac signal can be found by curve-fitting. Lessons can be drawn about the role of noise in measurement and about the very meaning of the result.