Abstract: The present invention relates to a method of verifying a measurement accuracy of a level gauge system. The method comprises determining a first measurement value indicative of a time-of-flight of a first electromagnetic reflection signal to a reference reflector and back; determining a measurement unit verification measurement value based on a response signal from a verification arrangement; determining a second measurement value indicative of a time-of-flight of a second electromagnetic reflection signal to the reference reflector and back; and determining a verification result based on the first measurement value, the second measurement value and the measurement unit verification measurement value. Through embodiments of the present invention, it will be verified that the measurement unit is functioning correctly and that level gauge system works as it should also after being reconnected to the propagation device.

Abstract: A method for determining the filling level of a product in a tank using electromagnetic signals, comprising: a) generating a transmission signal having a predetermined length; b) propagating the signal towards the product; c) receiving a reflected signal; d) determining whether the received signal overlaps the transmitted signal in the time-domain; e) setting an overlap-parameter to 1 if overlap is detected, otherwise setting the overlap-parameter to 0; if the state of the overlap parameter is not changed and if no overlap is detected, generate a signal having a length exceeding the previous length and repeat step b); and if the state of the overlap-parameter is not changed and if an overlap is detected, generate a signal having a length shorter than the previous length and repeat step b); and if the state of the overlap-parameter is changed, determine the filling level based on the length of the transmitted signal.

Abstract: A radar level gauge and a method for measurement of a distance to a surface of a product in a tank are disclosed. The radar level gauge comprises transceiver circuitry configured to transmit and receive electromagnetic signals, the transceiver circuitry comprises a frequency stabilizing feedback loop configured to generate the electromagnetic transmit signal in the form of a frequency sweep. The frequency stabilizing feedback loop is configured to generate an oscillation, forming a sinusoidal modulation of the frequency sweep. The radar level gauge further comprises a second mixer configured to mix an intermediate frequency signal and an integer multiple of the frequency of the sinusoidal modulation to provide an adjusted intermediate frequency signal, and processing circuitry configured to determine the distance based on the adjusted intermediate frequency signal. By providing a frequency sweep comprising a sinusoidal modulation, an improved sensitivity is achieved by the radar level gauge and method.

Abstract: Level measuring device which can compensate the distortions, caused by an STC filter, of the received signal, by measuring a reference signal which passes through the receiving branch and also through the STC filter, during the ongoing operation of the level measuring device or during manufacture. For example, after passing through the receiving branch, this reference signal can be fed to a microprocessor which can calculate the correction values of the IF signal therefrom. A switch can be provided which can switch over between the reference signal and the IF signal.

Abstract: There is disclosed herein a method of measuring and profiling a process liquid in a process vessel. The process liquid includes an emulsion layer between two media of differing dielectric constants. An electromagnetic signal is generated and transmitted along a probe, defining a transmission line, extending into the vessel. The transmission line comprises a conductor in contact with the process liquid with an insulating coating on the conductor to maximize signal penetration in the process liquid. A reflected signal is received from the transmission line and a programmed controller is operatively connected to the probe for measuring characteristics of reflected signal energy along the transmission line for profiling the emulsion layer.

Abstract: The present invention relates to a guided wave radar level gauge comprising a transceiver, processing circuitry and a single conductor probe comprising at least two elongate probe sections. A connector extending from a first end of the probe section comprises: an abutment portion having a diameter smaller than a diameter of the probe section, an intermediate portion, having a diameter smaller than the abutment portion, arranged between the probe section and the abutment portion and an outside threaded portion. A second end portion of the probe section comprises a sleeve comprising an inside threaded receiving portion receiving the connector; a passage through a sidewall of the sleeve being located off-center in relation to a longitudinal central axis of the probe section. The probe further comprises a locking pin to be arranged in the passage locking two assembled probe sections by limiting movement of the abutment portion in a longitudinal direction.

Abstract: A method and a device for determining a fill level of a medium using the radar principle that has a high degree of accuracy and reliability. In accordance with the method, an electromagnetic signal is transmitted from a transmitting device and an electromagnetic signal is received for determining the fill level. Thereby, a slope of the transmitting device relative to the force of gravity and an evaluation value dependent on the determined slope are identified for determining the fill level. Furthermore.

Abstract: A radar level gauge system for determining a filling level in a tank. The radar level gauge system comprises a transceiver, a horn antenna having a first opening connected to the transceiver and a second opening facing a surface of the product in the tank, and processing circuitry connected to the transceiver for determining the filling level based on an electromagnetic surface reflection signal. The horn antenna is configured in such a way that an electrical distance from the first opening to the second opening, along a path defined by an intersection between a wall of the horn antenna and a half-plane starting from and extending in parallel with a cone axis of the horn antenna, is different for different orientations of the half-plane with respect to the cone axis. Hereby, disturbance from an antenna reflection signal can be reduced, which provides for improved measurement of high filling levels.

Abstract: A guided wave radar transmitter for interface measurement comprises a probe defining a transmission line for sensing level of two immiscible liquids to define an interface therebetween. A pulse circuit generates pulses on the transmission line and receives a reflected signal from the transmission line. The reflected signal selectively includes a level pulse representing material level and an interface pulse representing interface level. A controller operates in an interface mode to determine the material level and the interface level responsive to receiving the level pulse and the interface pulse. The controller operates in a medium identification mode responsive to not receiving the interface pulse, comprising calculating an estimated amplitude of the level pulse for the two immiscible liquids and comparing actual amplitude of the level pulse to the estimated amplitude of the level pulse to identify the medium in the vessel.

Abstract: Stated is a process separation device for a fill-level measuring device including a pressure resistant feed-through for an inner conductor. The process separation device comprises an inner conductor, an outer conductor, a process side, a control side, and a feed-through. The inner conductor comprises a first conical region, and/or the outer conductor comprises a second conical region. The feed-through comprises the first conical region and/or is encompassed by the second conical region, and in this manner establishes a connection having positive fit between the inner conductor and the outer conductor.

Abstract: An FMCW radar level meter has an RF signal processing module, an intermediate frequency (IF) signal processing module, and a computation and display module. A signal generator of the RF signal processing module generates a first RF signal, which is radiated by an antenna to a measured object. The antenna received a second RF signal reflected by the measured object. The IF signal processing module processes the second RF signal and compares the first RF signal with the second RF signal. The computation and display module calculates and displays a distance between the FMCW radar level meter and the measured object. Using the RF signal processing module and the IF signal processing module to process the second RF signal, the issues of noise and temperature coefficient shift can be resolved.

Abstract: A radar-based fill level measurement device having a signal generator for the purpose of generating electromagnetic waves, and an antenna for the purpose of emitting the electromagnetic waves into a container, as well as for the purpose of receiving electromagnetic waves reflected out of the container, having a security device for the purpose of verifying the functional capability or improving the measurement quality of the radar-based fill level measurement device, wherein the security device has a reflector and an adjusting device, and is suitably designed to move the reflector between at least a first position, in which it reflects the electromagnetic waves, and a second position, in which it reflects the electromagnetic waves to a reduced degree, and wherein the security device has a drive which acts on the adjusting device.

Abstract: The present invention relates to a guided wave radar level gauge system for determining a filling level of a product contained in a tank. The level gauge system comprises a transceiver for transmitting and receiving electromagnetic signals, a probe extending into the tank and configured to guide the signals towards the surface and to guide reflected signals back to the transceiver, processing circuitry for determining the filing level based on the reflected signals, and a plurality of spacing elements arranged on the probe. Each spacing element comprises a shell structure having an ellipsoidal shape defining an ellipsoidal space, first and second shell openings at first and second locations of the shell, such that a passage through the shell openings defines a passage through the spherical space, wherein the probe extends through the passage, and a plurality of flow openings allowing fluid flow between the exterior and interior of the shell.

Abstract: Methods, apparatuses and systems for radio frequency identification (RFID)-enabled information collection are disclosed, including an enclosure, a collector coupled to the enclosure, an interrogator, a processor, and one or more RFID field sensors, each having an individual identification, disposed within the enclosure. In operation, the interrogator transmits an incident signal to the collector, causing the collector to generate an electromagnetic field within the enclosure. The electromagnetic field is affected by one or more influences. RFID sensors respond to the electromagnetic field by transmitting reflected signals containing the individual identifications of the responding RFID sensors to the interrogator. The interrogator receives the reflected signals, measures one or more returned signal strength indications (“RSSI”) of the reflected signals and sends the RSSI measurements and identification of the responding RFID sensors to the processor to determine one or more facts about the influences.

Abstract: A two-channel directional antenna for use in a radar level gauge. The antenna comprises a partition wall dividing the antenna into a first partition for emitting an electromagnetic transmit signal, and a second partition for receiving an electromagnetic echo signal, the partition wall having an outer potion located downstream in a direction of radiation of the antenna. The partition wall comprises an electromagnetic de-coupling structure, which is arranged to reduce any leakage of electromagnetic energy from the transmit signal into the echo signal. The electromagnetic de-coupling structure according to the present invention ensures that the leakage of transmit signal into the received signal is reduced to a satisfactory level.

Abstract: The present invention relates to a radar level gauge comprising a reference reflector arranged at a known reference reflector level in a tank. The radar level gauge is controllable between a filling level measuring state and a proof test state. In the proof test state, the radar level gauge is configured to determine a first verification level based on a reference reflector echo resulting from reflection of an electromagnetic transmit signal at the reference reflector; determine a second verification level based on a surface echo resulting from reflection of an electromagnetic transmit signal at the surface of the product; and provide the first verification level and the second verification level to allow determination of a proof test result based on at least the first verification level, the known reference reflector level and the second verification level.

Abstract: Apparatus for determining or monitoring fill level of a fill substance in a container, comprising: at least two antennas, wherein a first antenna transmits electromagnetic waves in the direction of the surface of the fill substance and a second antenna receives reflected waves; and at least one evaluation unit, which ascertains fill level in the container based on travel-time difference of transmitted and reflected electromagnetic waves, characterized in that the antennas are helical antennas, in order to transmit, respectively to receive, circularly polarized electromagnetic waves and the evaluation unit detects a rotational direction change between the transmitted wave and the reflected wave.

Abstract: A guided wave radar level gauge system, comprising a transmission line probe configured to support a first propagation mode such that it travels along the transmission line probe with a first propagation velocity exhibiting a first dependence on a dielectric constant of the surrounding medium, and support a second propagation mode such that it travels along the transmission line probe with a second propagation velocity exhibiting a second dependence, different from the first dependence, on the dielectric constant of the surrounding medium. The guided wave radar level gauge system further comprises processing circuitry connected to the transceiver for determining the filling level based on the reflected electromagnetic signal in the first propagation mode and the second propagation mode, and a known relation between the first dependence and the second dependence on the dielectric constant of the surrounding medium.

Abstract: A method for measurement of a distance to a surface of a product kept in a tank method comprises transmitting a pulse train of distinct carrier wave pulses having a duration greater than 1 microsecond and shorter than 100 milliseconds, the pulse train has an average duty cycle of less than 50 percent, each pulse has a defined center frequency, selected according to a frequency scheme within a predetermined frequency range, greater than 5% of an average center frequency. The method further comprises correlating actual phase properties of received pulses with expected phase properties to provide an updated estimation of the distance. The present invention is based on transmitting a set of carrier wave pulses, each having a distinct frequency selected within a frequency range. The method is therefore referred to as a Frequency Modulated Pulsed Wave (FMPW).

Abstract: A method of determining a filling level of a product contained in a tank, the method comprising the steps of: a) transmitting an electromagnetic probing signal towards a target area of a surface of the product; b) receiving a reflected probing signal being a reflection of the electromagnetic probing signal at the surface; c) determining a parameter value indicative of an amplitude of the reflected probing signal; if the parameter value is indicative of an amplitude larger than a predetermined threshold value: d) transmitting an electromagnetic measuring signal towards the target area of the surface; e) receiving a return signal being a reflection of the electromagnetic measuring signal at the surface; and f) determining the filling level based on a time relation between the electromagnetic measuring signal and the return signal.

Abstract: A fill level measuring device includes: a transmitting and receiving system for producing a higher frequency microwave signal and a lower frequency microwave signal. The transmitting and receiving system includes a single antenna, which has an internally funnel shaped horn and two hollow conductor segments connected with one another and connected to the horn. The antenna additionally includes, a coaxial conductor connection, via which the antenna is fed with the lower frequency microwave signal and the associated lower frequency echo signal is received. The antenna additionally includes, connected to a horn-remote end of that one of the two hollow conductor segments arranged on an end of the hollow conductor segment adjoining the horn, a hollow conductor connection, via which the antenna is fed with the higher frequency microwave signal and the associated higher frequency echo signal is received.

Abstract: A radar level gauging principle including transmitting at least two time separated carrier wave pulses having equal carrier frequencies, determining a change in phase shift associated with two pulses in the transmit signals having equal frequencies, comparing the change with a threshold value, and depending on a result of the comparing step, determining the distance based on a relationship between the transmit signals and the return signals. By comparing the actual phase resulting from two substantially identical pulses transmitted a certain time apart, an indication of a change of filling level can be obtained. This indication can then be used to initiate a full measurement cycle.

Abstract: A radar level gauge for determining a filling level of a product contained in a tank. The gauge has a sealing arrangement comprising a hollow housing, a conductor and a dielectric sleeve arranged inside the housing and surrounding the conductor. At least one gap is formed between the dielectric sleeve and an adjacent, electrically conducting surface, the gap having a first end which is open to an interior of the tank, so that in use, tank atmosphere may enter and condensate in the gap. The sealing arrangement further comprises an electrically conducting coating provided on a surface of the dielectric sleeve facing the gap, and in electrical contact with said adjacent, electrically conducting surface, so that an impedance between the electrically conducting coating and the adjacent electrically conducting surface is sufficiently low at an operating frequency of the gauge to reduce an influence of any medium present in the gap.

Abstract: A radar level gauging system for determining at least one process variable related to a distance to a surface of a product in a tank comprising transceiver circuitry, processing circuitry, a wave guiding structure arranged guide measurement signals towards the surface, and a radiator connected to the transceiver circuitry and arranged to emit the measurement signal into the wave guiding structure. The system further comprises a mode generator adapted to convert electromagnetic waves emitted from the radiator from a first propagation mode to a second propagation mode, wherein the mode generator includes a lens in the form of a body transparent to electromagnetic waves in the operating frequency range. With this design, electromagnetic waves having the first propagation mode emitted by the radiator into the lens will be reflected at least twice within the lens (first in the bottom surface and then in the upper surface).

Abstract: A radar level gauge using electromagnetic waves for determining a filling level of a product in a tank, comprising a transceiver, processing circuitry, a signal propagating device and a tank feed through structure. The tank feed through structure includes a fixed tank connection arranged to be secured to the tank, a tank connection adaptor arranged in a through hole of the fixed tank connection, a coupling arrangement arranged in the through hole and resting against the tank connection adaptor, and a fastening member attached to the fixed tank connection and securing the coupling arrangement between the tank connection adaptor and the fastening member.

Abstract: A radar level gauge using comprising a transceiver, processing circuitry, a signal propagating device, and a wave guide arrangement connecting the transceiver with the signal propagation device. The wave guide arrangement includes a hollow wave guide, a first filling member made of a first dielectric material, which first filling member is arranged inside the hollow wave guide, and a second filling member made of a second dielectric material, which second filling member is arranged inside the hollow wave guide outside the first filling member with respect to the tank. The second filling member is fixed in the wave guide at least in a direction out from the tank, and is configured to withstand temperatures up to 250 degrees Celsius. During conditions of temperatures sufficiently high to soften the inner filling member, the outer filling member will thus serve to prevent the first filling member from being forced out of the wave guide.

Abstract: A method for providing narrow-band interference unaffected measurement of a distance to a surface of a product kept in a tank, comprising mixing a return signal with a transmit signal to provide an intermediate frequency signal, and determining the distance, based on the intermediate frequency signal. The step of determining the distance further comprises dividing the intermediate frequency signal into a plurality of frequency portions, wherein each frequency portion corresponds to a frequency interval of the transmit signal, identifying disturbed frequency portions as frequency portions affected by narrow-band interference, and determining the distance based on frequency portions being unaffected by narrow-band interference. By dividing the IF-signal into frequency portions corresponding to frequency intervals of the transmit signal, frequency intervals where narrow-band interferences are present may be detected.

Abstract: A method of determining a filling level comprising transmitting a first transmit signal exhibiting a first ratio between bandwidth number of frequencies; receiving a first reflection signal; mixing the first transmit signal and the first reflection signal to form a first intermediate frequency signal; and determining a first data set indicative of a first set of surface echo candidates based on the first intermediate frequency signal. The method further comprises transmitting a second transmit signal exhibiting a second ratio between bandwidth and number of frequencies being different from the first ratio; receiving a second reflection signal; mixing the second transmit signal and the second reflection signal to form a second intermediate frequency signal; and determining a second data set indicative of a second set of surface echo candidates based on the second intermediate frequency signal. The filling level determined based on subsets of the first and second sets.

Abstract: The invention relates to a circuit arrangement for converting from a differential signal path (IFoutA-IFoutB) at the output of a mixer (18) to a signal path (Ssin gle) referenced to a reference potential (GND), wherein a controllable switch element (24a, 24b) is provided in each of the two single signal paths (IFoutA-IFoutB) of the differential signal path (IFoutA-IFoutB), wherein a first memory element (25) is connected in series with the two switch elements (24a, 24b), wherein there is provided for the two switch elements (24a, 24b), at least one control (23), which during a charging phase of the first memory element (25) connects the differential signal path (IFoutA-IFoutB) at the output of the mixer (18) with the first memory element (25) and applies the output signal on the differential output of the mixer (18) for charging the first memory element (25), and which during the discharging, respectively reverse charging, phase connects the first memory element (25) with the signal path referenced to the

Abstract: A method of monitoring operation of a radar level gauge system installed at a tank and arranged to determine a filling level of a product contained in the tank.

Abstract: A filling level measuring device antenna cover includes a base body and a plurality of circular fins concentrically arranged on the base body, wherein the fins and the base body consist of a plastic material. The fins and the base body are one piece and injection-moulded.

Abstract: Disclosed is a method of measuring the level of a liquid in a vessel, such as a chemical reactor, by radar. The method particularly pertains to situations wherein a supercritical fluid is present above the liquid. More particularly, the method serves to cope with the typical vigorous circumstances of a chemical reaction, such as urea synthesis. The invention foresees the use of a tube extending into the liquid, so as to guide the radar waves to the surface level of the liquid.

Abstract: A level gauge for detecting process variables related to a distance to a surface of a content in a tank, comprising a first and second functionally independent circuitry arrangements comprising transceiver circuitry and processing circuitry. The gauge further comprises a transmission line probe connected to the circuitry arrangements, the transmission line probe extending into the content in the tank and being adapted allow propagation of first and second transmission modes, and a feeding arrangement connected to couple electromagnetic signals into the probe in first and second propagation modes.

Abstract: The present invention relates to a guided wave radar level gauge system for determining a filling level of a product contained in a tank. The level gauge system comprises a transceiver for transmitting and receiving electromagnetic signals, a probe extending into the tank and configured to guide the signals towards the surface and to guide reflected signals back to the transceiver, processing circuitry for determining the filing level based on the reflected signals, and a plurality of spacing elements arranged on the probe. Each spacing element comprises a shell structure having an ellipsoidal shape defining an ellipsoidal space, first and second shell openings at first and second locations of the shell, such that a passage through the shell openings defines a passage through the spherical space, wherein the probe extends through the passage, and a plurality of flow openings allowing fluid flow between the exterior and interior of the shell.

Abstract: Level gauging including an approximation of a distance to the surface of a product kept in a tank. The approximation is determined by relating an amplitude of a first harmonic of an IF signal with an amplitude of a second harmonic of the IF signal. Basically, each harmonics represents a given distance range. By determining the received power in two or more harmonics, and correlating them to each other, the distance may be estimated. Depending on modulation and other parameters the distance dependence may be very different, and may be selected to suit the application.

Abstract: A guided wave radar level measurement instrument comprises a probe defining a transmission line for sensing material level. A probe interface circuit is connected to the probe for generating pulses on the transmission line and receiving reflected signals from the transmission line. The probe interface circuit comprises a transmit pulse generator for generating a transmit pulse, a sample pulse generator for generating a sample pulse, and a delay lock loop for controlling the transmit and sample pulse generators. The delay lock loop is controlled by a pulse repetition frequency having a duty cycle less than 50%.

Abstract: A process measurement instrument includes a fiducial and is adapted for detection of the fiducial. The instrument includes an interface circuit comprising a drive circuit for transmitting a pulse signal at the fiducial and at a target of interest and a receive circuit receiving reflected echoes of the pulse signal and developing an analog receive signal representative of the reflected echoes. A processing circuit is operatively coupled to the interface circuit for receiving the analog receive signal and comprising a threshold detector detecting if the analog receive signal is above a select threshold value. A controller is operatively coupled to the processing circuit and responsive to leading and trailing edges of the reflected echo for the fiducial and determining an average of the leading and trailing edges to determine location of the fiducial.

Abstract: A probe for use with a measurement instrument includes a circuit connected to the probe. The probe comprises a process adaptor for mounting to a process vessel and including a through bore extending from a connector end to a process end. A counterbore at the connector end defines a shoulder. A support assembly is received in the counterbore and rests on the shoulder. The support assembly comprises an annular rod support having a through opening with a tension rod extending through the opening and secured at opposite sides of the annular rod support. A locking nut secures the support assembly in the counterbore to maintain the annular rod support in compression. A probe rod extends from a process end of the tension rod. A seal assembly is operatively secured to the process adaptor at the connector end with the seal pin in electrical contact with a connector end of the tension rod.

Abstract: A guided wave radar level measurement instrument comprises a probe defining a transmission line for sensing material level. A pulse circuit is connected to the probe for generating pulses on the transmission line and receiving reflected signals from the transmission line. The pulse circuit comprises a pulse generator for generating a transmit pulse, a bridge circuit having a diode switched front end connected between the pulse generator and a differential circuit. The transmission line is connected to one side of the differential circuit. Generated pulses from the pulse generator are supplied to both sides of the differential circuit and reflected signals from the transmission line are supplied to one side of the differential circuit.

Abstract: A method for monitoring the surfaces of slag and molten metal in a mold of a continuous casting apparatus, using radar equipment is disclosed. The radar equipment emits a beam of electromagnetic waves having a bandwidth of at least 20 GHz. This also relates to an apparatus for using the method.

Abstract: A process measurement instrument including a fiducial and adapted for detection of the fiducial. The instrument comprises an interface circuit comprising a drive circuit for transmitting a pulse signal at the fiducial and at a target of interest and a receive circuit receiving reflected echoes of the pulse signal and developing an analog receive signal representative of the reflected echoes. A signal processing circuit is operatively coupled to the interface circuit for receiving the analog receive signal and determining characteristics of reflected echoes for the fiducial and the target of interest. The controller is operatively coupled to the signal processing circuit and includes a diagnostic routine responsive to the characteristics of the reflected echo for the fiducial in determining if a fiducial error condition exists.

Abstract: A radar level gauge system for determining a filling level in a tank. The radar level gauge system comprises a transceiver, a horn antenna having a first opening connected to the transceiver and a second opening facing a surface of the product in the tank, and processing circuitry connected to the transceiver for determining the filling level based on an electromagnetic surface reflection signal. The horn antenna is configured in such a way that an electrical distance from the first opening to the second opening, along a path defined by an intersection between a wall of the horn antenna and a half-plane starting from and extending in parallel with a cone axis of the horn antenna, is different for different orientations of the half-plane with respect to the cone axis. Hereby, disturbance from an antenna reflection signal can be reduced, which provides for improved measurement of high filling levels.

Abstract: A probe defining a transmission line is used with a measurement instrument including a pulse circuit connected to the probe for generating pulses on the transmission line and receiving reflected pulses on the transmission line. The probe comprises an adapter for mounting to a process vessel. A conductive outer sleeve is secured to the adapter. A center conductor is coaxial with the outer sleeve for conducting the pulses. The conductive outer sleeve has a connector end proximate the adapter and a distal end to extend into a processed liquid. The outer sleeve has a geometric discontinuity defining a referenced target producing an impedance change at a position between the adapter and the distal end at a location in a process vapor region above a processed liquid.

Abstract: A guided wave radar transmitter for interface measurement comprises a probe defining a transmission line for sensing level of two immiscible liquids to define an interface therebetween. A pulse circuit generates pulses on the transmission line and receives a reflected signal from the transmission line. The reflected signal selectively includes a level pulse representing material level and an interface pulse representing interface level. A controller operates in an interface mode to determine the material level and the interface level responsive to receiving the level pulse and the interface pulse. The controller operates in a medium identification mode responsive to not receiving the interface pulse, comprising calculating an estimated amplitude of the level pulse for the two immiscible liquids and comparing actual amplitude of the level pulse to the estimated amplitude of the level pulse to identify the medium in the vessel.

Abstract: Present novel and non-trivial optical, laser-based measuring systems and method are disclosed. An optical, laser-based, or LIDAR measuring apparatus is comprised of a radiation receiver/transmitter, a beam-forming optical element, a beam steering device comprised of a deviation optical element and at least one actuator used to steer the deviation optical element in response to drive signal(s) from a processor.

Abstract: A radar level gauge system comprising first pulse generating circuitry for generating a transmission signal, second pulse generating circuitry for generating a reference signal; and frequency control circuitry for controlling the second pulse generating circuitry to achieve a predetermined frequency difference between the transmission signal and the reference signal. The radar level gauge system further comprises first frequency selection circuitry configured to provide a higher order harmonic frequency component of the transmission signal to the frequency control circuitry; and second frequency selection circuitry configured to provide a higher order harmonic frequency component of the reference signal to the frequency control circuitry. The frequency control circuitry is configured to control the second pulse generating circuitry based on the higher order harmonic frequency component of the transmission signal and the higher order harmonic frequency component of the reference signal.

Abstract: A power management circuitry for a radar level gauge including a first voltage converter, having a low-voltage end for receiving a drive voltage from a power interface and a high-voltage end for supplying an intermediate voltage higher than the required operating voltage, a temporary energy store arranged to be charged by the intermediate voltage, a second voltage converter, having a high-voltage end for receiving an input voltage from the energy store, and a low-voltage end for providing the operating voltage lower than the input voltage. By storing energy at a higher voltage, a different type of energy store (e.g. low capacity capacitor) may be used. As a consequence, the cost and start-up time of the energy store is significantly reduced.

Abstract: The present invention relates to a method of determining a filling level of a product contained in a tank by propagating a first transmitted electromagnetic signal in a first frequency range and a second transmitted electromagnetic signal in a second frequency range different from the first frequency range along a transmission line probe towards a surface of the product in the tank, receiving a first reflected electromagnetic signal in the first frequency range and a second reflected electromagnetic signal in the second frequency range, and determining the filling level based on a time-of-flight of the first reflected electromagnetic signal and a difference in time-of-flight of the first reflected electromagnetic signal and the second reflected electromagnetic signal.

Abstract: A method for measurement of a distance to a surface of a product kept in a tank method comprises transmitting a pulse train of distinct carrier wave pulses having a duration greater than 1 microsecond and shorter than 100 milliseconds, the pulse train has an average duty cycle of less than 50 percent, each pulse has a defined center frequency, selected according to a frequency scheme within a predetermined frequency range, greater than 5% of an average center frequency. The method further comprises correlating actual phase properties of received pulses with expected phase properties to provide an updated estimation of the distance. The present invention is based on transmitting a set of carrier wave pulses, each having a distinct frequency selected within a frequency range. The method is therefore referred to as a Frequency Modulated Pulsed Wave (FMPW).

Abstract: The present invention relates to a method of verifying a measurement accuracy of a level gauge system. The method comprises determining a first measurement value indicative of a time-of-flight of a first electromagnetic reflection signal to a reference reflector and back; determining a measurement unit verification measurement value based on a response signal from a verification arrangement; determining a second measurement value indicative of a time-of-flight of a second electromagnetic reflection signal to the reference reflector and back; and determining a verification result based on the first measurement value, the second measurement value and the measurement unit verification measurement value. Through embodiments of the present invention, it will be verified that the measurement unit is functioning correctly and that level gauge system works as it should also after being reconnected to the propagation device.