A field device case is a metal field device case where a lead-in part for drawing a cable including an outer shield is provided on a tubular circumferential wall. The field device case includes: a first inner surface which is formed away from an opening end surface of the field device case in an axial direction orthogonal to the opening end surface; a second inner surface which is formed farther away from the opening end surface than the first inner surface in the axial direction; and a cable fixing member which is fixed to the first inner surface and allows the outer shield of the cable drawn by the lead-in part to be in contact with the second inner surface.

A method evaluates a frequency spectrum representative of at least one time-dependent signal, the at least one time dependent signal being derived from an output from a measuring device under predetermined measuring device operating conditions. The time-dependent signal, includes a portion being representative of a wanted signal, and a portion being representative of noise. The method includes the steps of determining, based on the frequency spectrum of the signal, a value representative of the noise floor, identifying, based on the frequency spectrum of the signal derived under the predetermined operating condition, a peak component, and if the peak component satisfies a relative peak criterion determined on the basis of the determined value representative of the noise floor, determining the wanted signal by applying a predetermined algorithm. The invention further relates to a method for determining flow of a measuring device, and a sensor.

The tube is used to conduct a fluid flowing through the tube in a specified flow direction and for this purpose comprises a tube wall (110), which encloses a lumen (100*) of the tube, and an interference body (120), which is arranged within the tube but is nevertheless connected to the tube wall at an inner face of the tube wall facing the lumen. In the tube according to the invention, the tube wall has a maximum wall thickness (s.sub.max) of more than 1 mm and at least two mutually spaced sub-segments (100-1, 100-2) with a respective wall thickness (s.sub.110-1, s.sub.110-2) that deviates from said maximum wall thickness (smax), wherein the sub-segment (100-1) is positioned upstream of the interference body (120) in the flow direction, and the sub-segment (100-2) is positioned downstream of the sub-segment (100-1) in the flow direction.

A configuration tool is for a vortex flowmeter having a flowtube, a bluff body positioned in the flowtube for shedding vortices in the fluid, and a pressure sensor configured to obtain a signal indicative of a time-varying fluid pressure having an oscillation associated with the vortices. The configuration tool includes a processor that determines a type of fluid flowing through the flowtube based on the amplitude of the oscillation. The processor sets a fluid-type setting of the vortex meter to match the determined type of fluid. An alarming system for a control system including such a flowmeter includes a processor that assesses a density of a fluid flowing through the flowtube based on the amplitude and compares the assessed density to a fluid density configuration setting. The processor activates an alarm if the difference between the assessed density and the fluid density configuration setting exceeds a threshold.

Provided is a flow measurement device capable of reliably correcting a measurement error of a flow rate of a fluid due to the temperature of the fluid. A bluff body 32 is inserted in a flow path 31 in a measuring pipe 30 to generate Karman vortices downstream of the bluff body 32, and a temperature sensor 36 is arranged downstream of a piezoelectric element 35 for sensing a change in the Karman vortices by converting the change into an electrical signal. The flow rate of the fluid can be corrected based on a relation of a vortex shedding frequency at a temperature of the fluid measured with the temperature sensor 36 and a vortex shedding frequency of the fluid measured at a reference temperature.

A vibronic sensor for monitoring a flowable medium, comprising: an oscillator to which a medium surrounding the oscillator can be applied; at least one electromechanical transducer for exciting the oscillator to mechanical vibrations in accordance with driver signals and/or for outputting transducer signals that depend on vibrations of the oscillator; an operating and evaluating unit for providing the driver signals for driving the electromechanical transducer, for capturing the transducer signals, and for determining the presence, the density, and/or the viscosity of the medium in accordance with the transducer signals, wherein the operating and evaluating unit is designed to detect whether the medium in the pipe has a flow velocity above a limit value on the basis of time-varying modifications of the transducer signals.

A flow measuring device operating on the vortex counter principle, comprises: a measuring tube; a blockage in the form of a bluff body in the measuring tube for bringing about a Karman vortex street with flow dependent vortex frequency; a first pressure fluctuation measuring arrangement for registering vortex related pressure fluctuations and for providing signals dependent on pressure fluctuations; a second pressure fluctuation measuring arrangement for registering vortex related pressure fluctuations and for providing signals dependent on pressure fluctuations. The first pressure fluctuation measuring arrangement is spaced in the longitudinal direction of the measuring tube from the second pressure fluctuation measuring arrangement. An evaluating unit for determining a vortex frequency and a flow measured value dependent thereon, and the evaluation unit is further adapted, based on the ratio of the amplitudes of the signals of the first pressure fluctuation measuring arrangement and the second pressure fluctuation measuring arrangement, or variables derived therefrom, to determine the current Reynolds number and/or the kinematic viscosity of the medium flowing in the measuring tube.

A method evaluates a frequency spectrum representative of at least one time-dependent signal, the at least one time dependent signal being derived from an output from a measuring device under predetermined measuring device operating conditions. The time-dependent signal, includes a portion being representative of a wanted signal, and a portion being representative of noise. The method includes the steps of determining, based on the frequency spectrum of the signal, a value representative of the noise floor, identifying, based on the frequency spectrum of the signal derived under the predetermined operating condition, a peak component, and if the peak component satisfies a relative peak criterion determined on the basis of the determined value representative of the noise floor, determining the wanted signal by applying a predetermined algorithm. The invention further relates to a method for determining flow of a measuring device, and a sensor.

An insertion-type flowmeter adapted for removable insertion into a fluid conduit includes an elongate body having a flow opening and a vortex-generating element disposed within the flow opening at distance from the opening entry that is correlated to the size of the flow opening to define a flow conditioning space in the flow opening between the opening entry and the vortex-generating element.

A flow feature detection method is described. The method includes storing a plurality of points at locations over a region in which vortex detection is to be performed. A value for each of a plurality of fluid flow parameters, such as velocity, pressure and density, is determined at each point. The points are grouped as being contained in either a flow feature portion or normal flow portion of the region according to one or more statistical distribution for the fluid flow parameters. A point is identified as being indicative of the flow feature by identifying multiple further points at least partially surrounding the point, and determining a plane in which the flow feature is identifiable based upon the relative values of the one or more fluid flow parameter for the further points. The method may be used to detect vortices and to identify a two-dimensional plane representative of a vortex.