MASS FLOW RATE MEASURING CIRCUIT OF CORIOLIS TYPE MASS FLOW RATE/DENSITY MEASURING METER

摘要

PROBLEM TO BE SOLVED: To make constitution fitted to a mass flow rate sensor which is provided with a measuring pipe having a vibrating frequency of 1 kHz order, and more simplify the constitution.;SOLUTION: This measuring circuit consists of a cross switch 35 which is connected with output terminals of first and second impedance transformers 31, 32 and has a first and a second input terminals, third and fourth impedance transformers 33, 34 which are connected with a first and a second output terminals of the cross switch and have remarkably high input resistances, low output resistances and one output terminal, respectively, first and second low- pass filters 37, 38 which are connected with output terminals of the third and the fourth impedance transformers 33, 34 and have one output terminal, pass bands and upper cut-off frequencies, respectively, first and second zero point passing point of time detectors 39, 40 which are connected with output terminals of the first and the second low-pass filters 37, 38, and a time to digital converter 41 which has a start input terminal, a stop input terminal and a clock input terminal and generates digital signals.;COPYRIGHT: (C)2001,JPO