Endress + Hauser Flowtec Ag

Michel Wagner

Rainer Höcker

Axel Pfau

Martin Arnold

Marc Hollmach

Markus Neuhaus

Fanos Christodoulou

A measurement system includes: a tube; a bluff body, situated in the lumen of the tube, for generating vortices in a flowing fluid such that a Karman vortex street is formed downstream of the bluff body; a vortex sensor, having a mechanical resonant frequency, for providing a vortex sensor signal which changes over time and contains a first component representing the vortex shedding frequency and which contains a second component representing the mechanical resonant frequency of the vortex sensor; and transducer electronics for evaluating the at least one vortex sensor signal and configured to do the following: to determine vortex frequency measurement values representing the shedding frequency using the first component and, if the first component is not present, not to provide flow parameter measurement values and to generate a message indicating the current flow speed is not lower than the current acoustic velocity of the flowing fluid.

Measurement system for measuring a flow parameter of a fluid flowing in a pipe

A thermal, flow measuring device and method for measuring the flow of a measured medium. During a heating phase of predetermined length a constant heating current of a first electrical current source flows through a first resistor. During a first measuring phase of predetermined length a constant measurement current of a second electrical current source flows through the first resistor. During the first measuring phase a first voltage falls across the first resistor, wherein during a second measuring phase of predetermined length during the first measuring cycle the constant measurement current of the second electrical current source flows through a second resistor. During the second measuring phase a second voltage falls across the second resistor, wherein during the heating phase the constant heating current of the first electrical current source flows through a shunt resistor, wherein during the heating phase a fifth voltage falls across the shunt resistor, wherein at least the first voltage, the second voltage and the fifth voltage are utilized for calculating the flow and wherein during the first measuring phase the constant heating current of the first electrical current source flows through a bypass resistor.

Method for operating a thermal, flow measuring device

Method and thermal, flow measuring device for determining at least one variable dependent on at least the chemical composition of a measured medium, wherein the measured medium has n components, wherein n is greater than or equal to two, wherein each mole fraction, volume fraction and/or mass fraction of m components of the medium is measured, wherein m is smaller than or equal to n minus one, wherein the mole fractions, volume fractions and/or mass fractions of the k components of the measured medium which are not measured, and wherein k is equal to n minus m, are established in such a manner, that the sum of the mole fractions, volume fractions and/or mass fractions of the n components amounts to one.

Method and thermal, flow measuring device for determining and/or monitoring at least one variable dependent on at least the chemical composition of a measured medium

A method for determining and/or monitoring aggregate state changes on a thermal, flow measuring device of at least a first part of a measured medium, wherein, as a result of the temperature of the medium being measured, as a result means of the chemical composition of the medium being measured and as a result of the partial pressure of the at least first part of the medium being measured and/or as a result of the total pressure of the medium being measured, at least one phase boundary line of the at least first part of the medium being measured is ascertained. At least a first measurement signal is provided from a temperature difference between a first temperature sensor and a second temperature sensor of the thermal, flow measuring device and/or from a heating power supplied the medium being measured, wherein, in the case of a state of the at least first part of the medium being measured in the region of the phase boundary line of the first part of the medium being measured, disturbances of predetermined type in the measurement signal are detected as aggregate state changes on the thermal flow device of the at least first part of the medium being measured.

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Birsfelden, Switzerland

Michel Wagner