On the Dynamics of Pneumatic Transmission Lines

An analysis of pneumatic transmission tubing dynamics based on a system of evenly distributed fixed parameters is presented. The driving-point impedance and the output-input frequency response of pneumatic tubing are derived from the frequency-response approach with small signals. Both calculated and experimental results are plotted for selected lengths of tubing. The correlation between calculated and test results for frequency response with amplitudes of ±5 per cent of conventional full-scale signal (3–15 psig) or less is good. The relations obtained are very useful in determining the effects of output loads on pneumatic-device dynamics and the limitations imposed on process control by various-length pneumatic transmission lines.