Effect of Tubing on Measurements of Small Transient Pressure Signals in Liquids

It is often necessary to connect the pressure transducer used for measurements of static and dynamic pressure signals to the pressure source by means of a connecting tube. The effects of the tube length and diameter on a relatively small step pressure signal in a liquid system have been studied experimentally and analyzed theoretically. Theoretical equations to predict the natural frequency and the damping coefficient of the system are obtained so that the proper length and diameter of tubing can be selected for minimum distortion of the step input signal. Agreement between theoretical predictions and experimental measurements was found to be reasonably good.