Study on Gibson Method of Flow Measuring : 1st Report, Influence of Leakage Flow

Abstract

In the case there exists a certain leakage flow at the time when the cut-off valve is completely closed, it has been understood that the Gibson Method is accompanied by an error, and as a result it has hitherto tended not to take any measurement in such case. The present report, however, describes the necessity of using a new calculation method of head recovery, which is different from the conventional one, in case there exists a fairly big amount of leakage flow at the time the cut-off valve is completely closed, and indicates that the same result as in the case where there exists no leakage flow, is obtained. Moreover, an assumed formula is derived for the error, which is resulted from the conventional formula, and it has been ascertained by an experiment that the conclusion is partly correct.