An unsteady flow measuring instrument for flow check of intravenous needles for single use

Flow capacity is often measured in the test of intravenous needles for single use. Steady flow measuring principle is generally used in the measuring instruments, makes the measuring system intricately, pressure loss of instrument itself large and measurement efficiency low. To solve the problems above, an unsteady flow measuring instrument is developed and revised, which improves the measurement accuracy, makes the measurement automatic, simplifies the measuring process, and reduces the costs. A multi-pieces marked flow check method is proposed for the minimum flow through every kinds of intravenous needle for single use.