FLOW RATE MEASURING APPARATUS

摘要

PROBLEM TO BE SOLVED: To quicken measurement while saving power by providing a main flow rate measuring means interposed between an inlet and an outlet, and a branch flow rate measuring means provided in a channel branched in the downstream of the outlet and altering the measuring method of the branch flow rate measuring means through a communication means when the flow rate measured by the main flow rate measuring means drops below a predetermined value. SOLUTION: When a comparison means 13r detects a fact that a measurement control means 13p measured a flow rate (not an integrated flow rate but an instantaneous flow rate) preset in the setting means 13q of a main flow rate measuring means 13 a signal is delivered to a measurement control means 15p through a communication means 16x and a communication means 16a set individually in branch flow rate measuring means 15a. When the flow rate decreases below a specified level, the measurement control means 15p alters the measurement time interval depending on the flow rate. For example, measurement is performed frequently when the flow rate is still high in order to sustain the flow rate accuracy and the number of times of measurement is decreased as the flow rate decreases. In the downstream of a branch channel 14, operation frequency of the branch flow rate measuring means 15a is altered when the flow rate of a main pipe decreases below a predetermined level.