An experimental correlation analyzer for measuring system dynamics

This paper describes an experimental analyzer which utilizes a modified form of the sine-wave correlation principle to measure the dynamic characteristics of systems including industrial processes and instruments. Relatively high accuracy is obtained even when the output is distorted by system nonlinearities or deteriorated by noise. Methods are presented for estimating the system noise characteristics and determining the signal-to-noise ratio improvement to be expected from the use of correlation. Examples are given for the application of the process analyzer to a simulated system, control system components, and an industrial process.