A flowmeter is disclosed. The flowmeter includes a vibratable conduit, and a driver connected to the conduit that is operable to impart motion to the conduit. A sensor is connected to the conduit and is operable to sense the motion of the conduit and generate a sensor signal. A controller is connected to receive the sensor signal. The controller is operable to detect a single-phase flow condition and process the sensor signal using a first process during the single-phase flow condition to generate a validated mass-flow measurement. The controller is also operable to detect a two-phase flow condition and process the sensor signal using a second process during the two-phase flow condition to generate the validated mass-flow measurement.

Correcting for two-phase flow in a digital flowmeter

In order to raise the measuring accuracy of a Coriolis-type mass flow rate meter in a cost-effective fashion, the latter comprises a measuring tube (4), a subcircuit measuring circuit and a subcircuit exciting circuit. Two vibration sensors (17, 18) and a vibration exciting (16) are arranged on the measuring tube. The vibration sensor (17) is assigned the amplifier (v1) in the subcircuit measuring circuit, and the vibration sensor (18) is assigned the amplifier (v2). Downstream of the two amplifiers are the summing stage (ss1) with a downstream integrating stage (ig), and the difference stage (ds). Downstream of the integrating stage (ig), the difference stage and the amplifier (v1) are the A/D converters (aw1, aw2, aw3), following which the digital processor (dp) is connected; it supplies the digital mass signal (m) and/or the digital density signal (d), as well as the gain control signal (v) for the amplifier (v2). The subcircuit exciting circuit contains the digital generator (dg), which supplies the digital exciting signal at the output (a1). The digital frequency controller (fr) is connected on the input side to the digital generator and to the digital processor, and on the output side to the frequency control input of the digital generator. The digital amplitude controller (ar1) is connected on the input side to the output (a5) of the digital processor, and on the output side to the amplitude control input of the digital generator.

Measuring and operating circuit of a Coriolis-type mass flow meter

A flowmeter is disclosed. The flowmeter includes a vibratable flowtube, and a driver connected to the flowtube that is operable to impart motion to the flowtube. A sensor is connected to the flowtube and is operable to sense the motion of the flowtube and generate a sensor signal. A controller is connected to receive the sensor signal. The controller is operable to determine an individual flow rate of each phase within a multi-phase flow through the flowtube.

Multi-phase coriolis flowmeter

A multi-phase process fluid is passed through a vibratable flowtube. Motion is induced in the vibratable flowtube. A first apparent property of the multi-phase process fluid based on the motion of the vibratable flowtube is determined, and an apparent intermediate value associated with the multi-phase process fluid based on the first apparent property is determined. A corrected intermediate value is determined based on a mapping between the intermediate value and the corrected intermediate value. A phase-specific property of a phase of the multi-phase process fluid is determined based on the corrected intermediate value.

Wet gas measurement

A micro fluid analyzer that may be highly sensitive, fast and very compact. The analyzer may use sufficiently low power per analysis to be easily implemented with an equivalently small battery pack or other portable power source. There may be energy conservation features in the analyzer, such as optimal adsorber film thicknesses in the pre-concentrator, concentrator and chromatographic separators. There may be special timing of the phased heating elements in the concentrators and separators to further reduce energy consumption. Various kinds of detectors and sensors may be incorporated in the analyzer for achieving low probability for false positives and detection versatility. There may be a controller that provides data acquisition and analyses, drive signals for control, management of wireless signal transmission and reception, processing, and other operational uses of the micro analyzer.

Phased micro analyzer VIII

A phase difference measuring apparatus for
accurately measuring the phase difference (fine time
difference) of two signals with the same frequency
with a reduced number of bits for A/D conversion is
disclosed. In addition to output signals of an
upstream side pickup and a downstream side pickup of
a mass flowmeter, an output signal of the
upstream side pickup or the downstream
side pickup
is supplied to a comparator, a PLL circuit, an
antialiase filter, a sample and hold circuit, and an
A/D converter. These circuits quantize these signals
and send the quantized signals to a band pass filter.
The band pass filter extracts a predetermined signal
component and outputs it to a DFT. The DFT performs
complex Fourier transformation on the input signal.
Thus, the phase difference between two signals with
the same frequency (such as an upstream side pickup
signal and a downstream side pickup signal) can be
accurately detected with a reduced number of bits for
each of the A/D converters.

Phase difference measuring apparatus and mass flowmeter thereof

A phase difference measuring apparatus for
precisely measuring a phase difference between two
input signals having the same frequency sent from,
for example, a Coriolis type mass flowmeter. A
differential amplifier in the apparatus provides the
sum or difference of the two input signals and a
multiplexor sequentially selects and outputs to an
A/D converter the two input signals and the output of
the differential amplifier. The A/D converter
converts the output of the multiplexor into digital
data and a digital signal processor or a
microcomputer calculates the phase difference between
the two input signals based on the converted digital
data. The apparatus may further comprise a function
that an error caused by the difference of the
transfer characteristics of a filter and the A/D
converter is compensated using a reference signal
which is selected from the two input signals.

o Fuji Electric Co. Ltd. Yoshimura

Papers

Phase difference measuring apparatus and mass flowmeter thereof

Phase difference measuring apparatus for measuring phase difference between input signals