Abstract: For calibrating high frequency based field devices, a first switching unit is provided between the antenna arrangement and the transmission amplifier and receiving amplifier of the field device. For ascertaining the corresponding calibration factors, the first switching unit can assume switch positions at which the signal production unit and/or the evaluation unit are/is connected with the antenna arrangement, and at which the transmission path and/or the receiving path are/is connected with an attenuation element via which the transmission path is connectable with the receiving path. An evaluation unit of the field device ascertains at least at these switch positions the corresponding characteristic variable to use these in the later measurement operation as calibration factors. Advantageous with this kind of calibration of the invention is that possible couplings of the amplifiers are compensable.

Abstract: A method for determining a deposit property of a variable deposit on an end face of a first microwave antenna of an assembly for determining a property of a multiphase medium that is to be conveyed, wherein the first microwave antenna is arranged in a first receptacle of the measuring pipe in a medium-contacting manner, wherein the method comprises emitting an excitation signal by means of the first microwave antenna, wherein the excitation signal comprises a sequence of high-frequency signals; receiving a reflected excitation signal by means of the first microwave antenna; determining a first test quantity on the basis of the reflected excitation signal; and determining on the basis of the first test quantity the deposit property of the variable deposit, in particular a variable dependent on a deposit thickness of the variable deposit.

Abstract: An antenna for high-frequency based measuring devices for determining a dielectric value of media is based on a high-frequency waveguide. The high-frequency signal is coupled in or out via a coaxial conductor that runs orthogonally through the axis of the high-frequency waveguide for this purpose. The conductor termination for the coaxial conductor extends extensively beyond the high-frequency waveguide in such a way that the coaxial conductor forms a defined capacitance in this region. In this way, the coaxial conductor is optimally matched to the high-frequency waveguide without having to integrate additional electrical components for this purpose.

Abstract: A method for determining a coating property of a variable coating on an inner circumferential surface of a measuring tube includes emitting an excitation signal from the first microwave antenna, wherein the excitation signal comprises a sequence of high-frequency signals; receiving the excitation signal by the second microwave antenna; determining a first test variable from the received excitation signal and/or from an integral transform of the received excitation signal, wherein the first test variable is characteristic of the propagation of the excitation signal along a first propagation path, wherein the first propagation path describes an at least partial propagation of the excitation signal by the variable coating on the inner circumferential surface; and determining the coating property of the variable coating, in particular a variable dependent upon a coating thickness of the variable coating, based upon the first test variable.

Abstract: The present disclosure relates to a measuring assembly comprising: a metallic measuring tube open on both sides for carrying a medium, wherein the measuring tube has an outer circumferential surface, an inner circumferential surface, and at least two apertures, wherein the two apertures extend from the outer circumferential surface to the inner circumferential surface; a dielectric cladding layer, which rests on the inner circumferential surface of the measuring tube; a first microwave antenna, which is arranged in the measuring tube and with which contact can be made through the first aperture; a second microwave antenna which is arranged in the measuring tube and with which contact can be made through the second aperture; wherein the dielectric cladding layer forms a dielectric waveguide, via which microwaves can, at least to some extent, reach from the first microwave antenna to the second microwave antenna.

Abstract: Disclosed is a device for measuring fill level of a liquid comprising: a measuring tube having a tube wall extending between first and second terminal openings and which surrounds a volume for guiding the liquid, wherein a tube axis extends between the two tube openings; a first conductor extending at least sectionally around the volume and is electrically insulated from the volume; a second conductor extending at least sectionally around the volume and is electrically insulated from the first conductor and from the volume, wherein the two conductors extend essentially in parallel with one another and form a waveguide for microwaves; an HF circuit for in-coupling a microwave signal into the waveguide and for receiving reflected microwave signals out-coupled from the waveguide; an operating and evaluating circuit for determining fill level of the liquid in the measuring tube based on received microwave signals.

Abstract: Disclosed is a method for determining of fat content of milk having variable solids fractions and flowing with variable gas content in a pipeline. The method includes ascertaining a velocity of sound and an average density value for the milk based on eigenfrequencies of at least two bending oscillation wanted modes of measuring tubes of a densimeter arranged in the pipeline. The method further includes ascertaining a static pressure in the pipeline; a gas volume fraction based on the velocity of sound; the average density; the pressure; a density of the milk without gas content based on the average density and the gas volume fraction; and a permittivity of the milk based on a propagation velocity and/or an absorption of microwaves in the milk. The fat fraction is calculated based on the density of the milk without gas content and on the effective permittivity.

Abstract: A method of monitoring a condition prevailing inside a piping system with respect to an impairment due to accretion, abrasion or corrosion caused by fluid(s) flowing through the piping system is disclosed, comprising the steps of: installing at least two measurement devices susceptible to an impairment and configured to measure variables indicative of the impairment; wherein the measured variables include at least two variables exhibiting a different dependency on the impairment; continuously recording data including time series of measured values of the variables measured; based on training data included in the data determining a dynamic reference behavior of the variables corresponding to time dependent distributions of values of the variables to be expected of the measured values when the measurement devices are unimpaired; repeatedly determining a deviation between a monitored behavior of the measured values of the variables and the reference behavior.

Abstract: An antenna assembly for emitting microwaves comprises a dielectric hollow conductor element and a support element, wherein the hollow conductor element has an electrically conductive surface along a circumferential lateral face, the hollow conductor element has an electrically non-conductive emission face, and the hollow conductor element has a coupler receptacle. The support element contains a material having a modulus of elasticity of no less than 50 GPa. The support element surrounds the hollow conductor element at least along the lateral face. The hollow conductor element is fixed in the support element. The support element has an emission opening, and the emission face aligns with the emission opening. The hollow conductor element has a permittivity of no less than 8 at 2 GHz, the hollow conductor element containing a ceramic material, in particular aluminium oxide, zirconium oxide or titanium oxide.

Abstract: The present disclosure relates to a measuring assembly comprising: a metallic measuring tube open on both sides for carrying a medium, wherein the measuring tube has an outer circumferential surface, an inner circumferential surface, and at least two apertures, wherein the two apertures extend from the outer circumferential surface to the inner circumferential surface; a dielectric cladding layer, which rests on the inner circumferential surface of the measuring tube; a first microwave antenna, which is arranged in the measuring tube and with which contact can be made through the first aperture; a second microwave antenna which is arranged in the measuring tube and with which contact can be made through the second aperture; wherein the dielectric cladding layer forms a dielectric waveguide, via which microwaves can, at least to some extent, reach from the first microwave antenna to the second microwave antenna.

Abstract: Disclosed is a measuring device for measuring a dielectric constant of filling material in a container. The measuring device includes: a signal generating unit designed to drive a transmitter electrode with an AC voltage such that the transmitter electrode emits a radar signal in the direction of the filling material; a receiver electrode arrangeable in the container to receive the radar signal following passage through the filling material; and an evaluation unit configured to ascertain an amplitude, a phase shift, and/or a signal propagation time between transmitter electrode and receiver electrode on the basis of the received radar signal and to determine the dielectric constant on the basis of the ascertained signal propagation time, phase shift, and/or the amplitude.

Abstract: The present disclosure relates to a measuring assembly comprising: a metallic measuring tube open on both sides for carrying a medium, wherein the measuring tube has an outer circumferential surface, an inner circumferential surface, and at least two apertures, wherein the two apertures extend from the outer circumferential surface to the inner circumferential surface; a dielectric cladding layer, which rests on the inner circumferential surface of the measuring tube; a first microwave antenna, which is arranged in the measuring tube and with which contact can be made through the first aperture; a second microwave antenna which is arranged in the measuring tube and with which contact can be made through the second aperture; wherein the dielectric cladding layer forms a dielectric waveguide, via which microwaves can, at least to some extent, reach from the first microwave antenna to the second microwave antenna.

Abstract: Disclosed is a device for measuring fill level of a liquid comprising: a measuring tube having a tube wall extending between first and second terminal openings and which surrounds a volume for guiding the liquid, wherein a tube axis extends between the two tube openings; a first conductor extending at least sectionally around the volume and is electrically insulated from the volume; a second conductor extending at least sectionally around the volume and is electrically insulated from the first conductor and from the volume, wherein the two conductors extend essentially in parallel with one another and form a waveguide for microwaves; an HF circuit for in-coupling a microwave signal into the waveguide and for receiving reflected microwave signals out-coupled from the waveguide; an operating and evaluating circuit for determining fill level of the liquid in the measuring tube based on received microwave signals.

Abstract: Method for continuous determining of fat content of milk having variable solids fractions and flowing with variable gas content in a pipeline, comprising: ascertaining a value for velocity of sound and an average density value for milk flowing in the pipeline based on eigenfrequencies of at least two bending oscillation wanted modes of measuring tubes of a densimeter arranged in the pipeline; ascertaining a value for static pressure in the pipeline by means of a pressure sensor connected to the pipeline; ascertaining a value for gas volume fraction based on the value for the velocity of sound, the value for the average density and the value for the pressure; ascertaining a value of density of milk flowing in the pipeline without gas content based on the value for the average density and based on the value for the gas volume fraction; ascertaining a value for permittivity of milk flowing in the pipeline based on at least one measuring of propagation velocity and/or absorption of microwaves in the milk by me

Abstract: The present disclosure relates to a measuring assembly comprising: a metallic measuring tube open on both sides for carrying a medium, wherein the measuring tube has an outer circumferential surface, an inner circumferential surface, and at least two apertures, wherein the two apertures extend from the outer circumferential surface to the inner circumferential surface; a dielectric cladding layer, which rests on the inner circumferential surface of the measuring tube; a first microwave antenna, which is arranged in the measuring tube and with which contact can be made through the first aperture; a second microwave antenna which is arranged in the measuring tube and with which contact can be made through the second aperture; wherein the dielectric cladding layer forms a dielectric waveguide, via which microwaves can, at least to some extent, reach from the first microwave antenna to the second microwave antenna.