Mass flowmeter

摘要

A mass flowmeter has a U-shaped sensor tube provided on a support base which is supported on a vibration absorbing member, and both ends of the sensor tube are respectively connected to an inlet and an outlet of a manifold. Vibrators are provided at an intermediate part of each straight tube part provided between the inlet and outlet sides of the sensor tube. Pickups are provided on the upstream and downstream sides of each vibrator so as to detect the displacement of the sensor tube. An external vibration is in an opposite direction between the inlet and outlet sides relative to the vibrating direction. Hence, outputs of the pickups located on the upstream sides of the vibrators are added, and outputs of the pickups located on the downstream sides of the vibrators are added. The external vibration is cancelled by obtaining a phase difference of the two added values.