Abstract: The present disclosure relates to a method for safe and exact ascertaining of fill level of a fill substance located in a container by means of an ultrasonic, or radar-based, fill level measuring device. In such case, the method is distinguished by the feature that the evaluation curve created based on the reflected received signal is differently greatly smoothed as a function of measured distance. To achieve this, the evaluation curve can be specially filtered, depending on the application. In this way, noise fractions and disturbance echoes can be efficiently suppressed, without unnecessarily limiting the accuracy of the fill level measurement.

Abstract: Disclosed is a method for a radar-based fill level measurement according to the pulse transit time method. Also disclosed a fill level measuring device for carrying out said method. On the basis of an evaluation signal, the relation between the clock rate and the sampling rate, and a predefined target relation, an evaluation curve is generated. The fill level is thereby determined on the basis of said evaluation curve. The evaluation curve is generated by means of temporal expansion or compression of the evaluation signal, wherein the compression or the expansion is carried out as a function of a ratio between the measured relation and the target relation. Any deviation of the sampling rate from the setpoint value of the sampling rate, for example due to faulty control, is compensated. Thus, the potentially attainable accuracy of the fill level measurement is increased due to the invention.

Abstract: An FMCW-radar based distance measuring device is characterized in that, in addition to analogue high-pass and low-pass filtering, the evaluation signal typical for FMCW additionally undergoes subsequent digital filtering. In this case, the analogue/digital conversion takes place by oversampling. As a result, according to the invention, all those frequencies in the evaluation signal that are above or below the frequency corresponding to the distance of the object are effectively suppressed. At the same time, the analogue filters can be constructed with a very low level of complexity. The space requirement and the costs of the analogue components is reduced thereby. In addition, the dependence on temperature of the distance measuring device is reduced thereby. The potentially high distance resolution is also maintained.

Abstract: Disclosed is a method for determining the serviceability of a fill-level measuring device that includes at least one electronic unit. The method can be applied to any type of field device that includes at least one electronic unit supplied by an energy store of the field device. The method includes: measuring the capacitance of the energy store and/or measuring the power withdrawal at the energy store. The field device is classified as not operationally reliable if the capacitance of the energy store is below a defined minimum capacitance and/or if the power withdrawal deviates from a predefined normal consumption. An advantage of the method according to the invention is that, in addition to the functional diagnosis, in particular also a prediction up to the expected elapsing of the remaining operating time can be created by recording the power withdrawal or the capacitance over progressive measurement cycles.

Abstract: Disclosed is a method for a radar-based fill level measurement according to the pulse transit time method. Also disclosed a fill level measuring device for carrying out said method. On the basis of an evaluation signal, the relation between the clock rate and the sampling rate, and a predefined target relation, an evaluation curve is generated. The fill level is thereby determined on the basis of said evaluation curve. The evaluation curve is generated by means of temporal expansion or compression of the evaluation signal, wherein the compression or the expansion is carried out as a function of a ratio between the measured relation and the target relation. Any deviation of the sampling rate from the setpoint value of the sampling rate, for example due to faulty control, is compensated. Thus, the potentially attainable accuracy of the fill level measurement is increased due to the invention.

Abstract: Disclosed is a method for detecting an event-based state, such as foam formation or a working stirring mechanism in a container during a radar-based measurement of a fill level of a filler located in a container. The method includes: generating an analysis curve and detecting a specified characteristic value of the analysis curve within at least one specified sub-region of the measurement region. The characteristic value can be the amplitude of a local maximum or the area under the analysis curve for example. A change or a dispersion of the characteristic value is ascertained over proceeding measurement cycles. The fill level measuring device detects the event-based state if the change or the dispersion exceeds a corresponding threshold. Thus, the occurrence of different events in the container can be imparted to a system controller automatically and without additional measurement instruments.

Abstract: Disclosed are methods for checking the operational reliability of a radar-based fill level measurement device, which operates according to the pulse time-of-flight method. The methods include detecting controlled variables of the fill level measurement device, such as the signal amplification or the sampling rate. By comparing the controlled variable with a corresponding limit value, it can be determined whether the fill level measurement device is operationally reliable or whether the operational reliability of the fill level measurement device has been lost with increasing operating times because of the degradation of electrical components. It is also advantageous that, on the basis of the methods according to the invention, it is possible to make a prediction according to the principle of “predictive maintenance” regarding how much remaining operating time is estimated to be left until a possible functional failure of the fill level measurement device.

Abstract: The present disclosure relates to a method for safe and exact ascertaining of fill level of a fill substance located in a container by means of an ultrasonic, or radar-based, fill level measuring device. In such case, the method is distinguished by the feature that the evaluation curve created based on the reflected received signal is differently greatly smoothed as a function of measured distance. To achieve this, the evaluation curve can be specially filtered, depending on the application. In this way, noise fractions and disturbance echoes can be efficiently suppressed, without unnecessarily limiting the accuracy of the fill level measurement.

Abstract: A method for checking the functional ability of an FMCW-based fill-level measuring device, which serves for measuring the fill level of a fill substance located in a container, as well as to a fill-level measuring device suitable for performing this method. For checking the functional ability, a microwave signal is produced, whose frequency change differs from the frequency change of the measurement signal used during regular measurement operation. By comparing the frequency of the difference signal resulting from the microwave signal with a predetermined reference frequency, it is ascertained, whether the fill-level measuring device is functionally able. Thus, the fill-level measuring device detects, independently, whether it is functionally able, or whether an error is present, caused principally by device-internal disturbance signals. This offers, especially, a clear advantage as regards meeting safety standards for the field device.

Abstract: A method for determining an inner diameter of a sounding tube, which, for measuring the fill level of a fill substance located in a process space of a container, extends in the process space, or is placed alongside the container and connected with the process space. The method can be implemented in the case of a fill-level measuring device working according to the FMCW-principle. Besides the intermediate frequency of the difference signal, also its phase shift is ascertained, wherein the exact tube inner diameter can be determined based on the phase shift. An advantage of the method is that the fill-level measuring device with the help of the then exactly known tube diameter can be recalibrated and accordingly the fill level determined more exactly. The exact tube inner diameter does not have to have been previously known.

Abstract: A method for measuring a fill level of a fill substance in a container with a fill-level measuring device working according to the travel time principle. The fill-level measuring device in measurement operation sends transmission signals toward the fill substance in the container and, based on their signal fractions reflected back in the container, derives echo functions, which give the amplitudes of the signal fractions as a function of their travel time.

Abstract: A method for measuring fill level and a measuring device for performing the method, wherein, in measuring cycles following one after the other, signal pulses of predetermined frequency sent by means of a transmitting and receiving system with a predetermined repetition frequency into a container, and their signal components reflected back in the container in the direction of the transmitting and receiving system after a travel time dependent on their traveled path, are received as received signal. A fill level is measured taking into consideration a phase relationship between the transmitted and received signals related physically with the fill level to be measured.

Abstract: A method for measuring fill level of a fill substance. Transmission signals are sent and their fractions reflected on reflectors in the container and received as received signals. Based on the received, echo functions are derived and wanted echos of predetermined wanted echo types respectively contained in the echo functions and identifiable based on predetermined echo recognition methods are ascertained. Each wanted echo is a local maximum and is attributable to a reflection on a reflector associated with its wanted echo type. Echo quality of each wanted echo is determined. The echo quality is higher, the more peak shaped the echo function is in the region of the respective wanted echo, and the fill level is determined taking into consideration echo qualities of the wanted echos.

Abstract: In a method for ascertaining and monitoring fill level of a medium in a container by means of a field device using a travel time measuring method, wherein transmission signals are transmitted toward the medium and reflection signals are received; the received reflection signals are registered as echo signals in an echo function, or envelope curve, dependent on travel time or travel distance; by means of an echo search algorithm, at least one wanted echo signal is ascertained in the echo function, or envelope curve; by means of at least one filter with filter parameters the echo function, or the envelope curve, is preprocessed; at least a first filter range with a first width is predetermined at the position of the wanted echo signal in the echo function, or in the envelope curve, and at least three filter ranges are formed in the echo function, or in the envelope curve.

Abstract: A method for checking the functional ability of an FMCW-based fill-level measuring device, which serves for measuring the fill level of a fill substance located in a container, as well as to a fill-level measuring device suitable for performing this method. For checking the functional ability, a microwave signal is produced, whose frequency change differs from the frequency change of the measurement signal used during regular measurement operation. By comparing the frequency of the difference signal resulting from the microwave signal with a predetermined reference frequency, it is ascertained, whether the fill-level measuring device is functionally able. Thus, the fill-level measuring device detects, independently, whether it is functionally able, or whether an error is present, caused principally by device-internal disturbance signals. This offers, especially, a clear advantage as regards meeting safety standards for the field device.

Abstract: A method for determining an inner diameter of a sounding tube, which, for measuring the fill level of a fill substance located in a process space of a container, extends in the process space, or is placed alongside the container and connected with the process space. The method can be implemented in the case of a fill-level measuring device working according to the FMCW-principle. Besides the intermediate frequency of the difference signal, also its phase shift is ascertained, wherein the exact tube inner diameter can be determined based on the phase shift. An advantage of the method is that the fill-level measuring device with the help of the then exactly known tube diameter can be recalibrated and accordingly the fill level determined more exactly. The exact tube inner diameter does not have to have been previously known.

Abstract: A method for determining and/or monitoring fill level of a medium in a container with a measuring device, which works according to the travel time measuring method, wherein measurement signals are transmitted toward the medium and are received, wherein from the high-frequency total measurement signal, composed by superimposing the transmitted measurement signals, the reflected wanted echo signals and the disturbance echo signals, a raw echo curve or digitized envelope curve is ascertained. The wanted echo signals and/or the disturbance echo signals in the raw echo curve or the digitized envelope curve are ascertained based on an ideal echo curve, which shows the amplitude of the echo signals of an ideal reflector as a function of the distance from the ideal reflector, and based on the ascertained wanted echo signal the fill level is determined.

Abstract: Apparatus for measuring fill level of a fill substance in a container, comprising a fill-level sensor, which is so embodied that it determines fill level via a travel-time difference measuring method or a capacitive measuring method, a limit-level sensor for monitoring a limit-level of the fill substance in the container, and an electronics unit, which is associated with the fill-level sensor and/or the limit-level sensor. The electronics unit determines based on measurement data of the fill-level sensor the fill level of the fill substance in the container, and wherein the electronics unit monitors based on measurement data of the limit-level sensor (2) the limit-level of the fill substance in the container.

Abstract: A method for ascertaining and monitoring fill level of a medium in a container using a travel time measuring method, wherein transmission signals are transmitted toward the medium and reflection signals are received. The received reflection signals are registered as echo signals in an echo function dependent on travel time. Based on known measuring device- and container-specific reflection planes, possible reflection regions in the echo function are calculated by means of an evaluation algorithm. In the calculated reflection regions, the disturbance echo signals and/or the multiecho signals in the echo function are classified, wherein non-classified reflection signals are ascertained and checked as wanted echo signals by means of a search algorithm, wherein, from a position and/or an amplitude of at least one wanted echo signal, fill level is determined, and wherein the measured value of fill level is output.

Abstract: In a method for ascertaining and monitoring fill level of a medium in a container by means of a field device using a travel time measuring method, wherein transmission signals are transmitted toward the medium and reflection signals are received; the received reflection signals are registered as echo signals in an echo function, respectively envelope curve, dependent on travel time or travel distance; by means of an echo search algorithm, at least one wanted echo signal is ascertained in the echo function, respectively envelope curve; by means of at least one filter with filter parameters the echo function, respectively the envelope curve, is preprocessed; at least a first filter range with a first width is predetermined at the position of the wanted echo signal in the echo function, respectively in the envelope curve, and at least three filter ranges are formed in the echo function, respectively in the envelope curve.