Non-interacting method for switching flows of liquid, for use in calibrating volumetric flow meter, involves decreasing flow of liquid through valves, so that liquid from supply line partially flows into derivative

摘要

The method involves causing flow of liquid through supply line (14) with supply flow rate (Q0) which is the sum of flow rates (Q1,Q2) corresponding to valves (16,18). Flow of liquid through valves is decreased, so that liquid from supply line partially flows into derivative (52), and liquid pressure or supply flow rate in upstream of valves is in predetermined pressure or predetermined flow range. Independent claims are included for the following: (1) flow switching device; and (2) calibration apparatus for calibrating volumetric flow meter.