MASS FLOW METER

Japanese Patent JPH0377021

A

PURPOSE:To protect sensor tubes when used for flow rate measurement of high-viscosity fluid by providing an interlock circuit which stops flow rate measurement when the temp. detected by a temp. sensor is lower than a set temp. CONSTITUTION:Coriolis force is generated and the sensor tubes 5, 6 oscillate when the fluid flows in the sensor tubes 5, 6. The oscillation is detected by pickups 10, 11, by which the time difference/voltage conversion 20 and voltage/ frequency conversion 21 of the oscillation are executed. A flow rate signal is detected via a flow rate computing circuit 22. The flow rate signal is subjected to a temp. correction via the temp. sensor 24, a resistance/voltage converting circuit 25 and a temp. correcting circuit 26. A comparator circuit 30 compares the output voltage Va from the circuit 25 and the output voltage Vb of the circuit 25 and the output voltage Vb of the circuit 25 corresponding to the temp. at which the possibility of the deformation and rupture of the sensor tubes 5, 6 arises on increasing of the viscosity of the fluid. The circuit outputs a signal when Va