FIELD: instrumentation.
SUBSTANCE: Coriolis flow metre detects at least one of phase difference and oscillation frequency proportional to Coriolis force acting to at least one or two flow metre tubes to obtainer either mass flow rate or fluid density. Signal processing device comprises: ADCs to convert analogue signals fro oscillation transducers into digital signals. Plus frequency metre unit to measures oscillation frequencies θ of at least one flow metre tube or two such tubes. Plus transmitter to generate frequency-coded signal that features frequency θ(1-1/N) defined as frequencies of said frequency-coded signal from frequency metre unit. It incorporates two orthogonal frequency transducers to convert two digital signals from said frequency-coded signal generated by said transmitter that correspond to two frequency detectors. Said signals output from ADCs. Besides it generates digital signals with frequency defined as 1/N of frequencies of two digital signals. Thus, phase difference is obtained using two digital signals generated by two orthogonal frequency converters.
EFFECT: continuous high-precision measurement.
8 cl, 32 dwg
