A Modified Technique of Flow Transducer Using Bourdon Tube as Primary Sensing Element

The pressure head at a point inside a flowing fluid through a pipeline decreases with the increase of flow rate according to Bernoulli´s equation. The measurement of flow rate by measuring this pressure is not generally used since decrease of pressure is very small compared with static pressure at no flow. In this paper, a modified differential inductance-type technique has been developed to measure the flow rate of a fluid by measuring only this change in pressure without using any obstruction in the pipeline. A differential inductance-type pressure transducer using two identical Bourdon tubes as the primary sensing elements, has been designed and developed to measure the small decrease of pressure due to flow of fluid in a horizontal pipeline. The transducer has been used to measure the flow rate of tap water through a pipeline. The basic theoretical equations describing the operation of the transducer have been derived. The transducer has been experimentally tested and the experimental results are reported in this paper. The experimental characteristic is found to follow the theoretical equations with good repeatability.