Abstract: A method of detecting leakage, comprising the steps of: performing a sequence of monitoring operations; and providing, when it is determined that leakage is present, a signal indicative of detected leakage. Each monitoring operation includes the steps of: generating a transmit signal exhibiting a time-varying frequency; receiving a reflection signal resulting from reflection of the transmit signal at the surface; forming an intermediate frequency signal for the present monitoring operation based on the transmit signal and the reflection signal; determining a phase of the intermediate frequency signal for the present monitoring operation; determining, based on the phase for the present monitoring operation and the phase associated with at least one previous monitoring operation, a measure indicative of a present rate of change of the phase; comparing the measure with a predefined threshold value; and determining a presence of leakage based on the comparison.

Abstract: A filling level determination system, for determining a filling level of a product in a tank, comprising a measurement unit for arrangement at a measurement position, the measurement unit including a transceiver; and an antenna arrangement coupled to the transceiver for radiating an electromagnetic transmit signal generated by the transceiver from the measurement position towards a target position on the tank wall, and for returning an electromagnetic first reflection signal resulting from reflection of the transmit signal at the target position back towards the transceiver; and processing circuitry coupled to the transceiver of the measurement unit and being configured to determine the filling level based on tank deformation data indicative of a known relation between the level of the product in the tank and deformation of the tank at the first target position, and a timing relation between the first transmit signal and the first reflection signal.

Abstract: The present invention relates to a method of proof-testing a radar level gauge system arranged to determine a filling level of a product in a tank, the method comprising the steps of: transmitting an electromagnetic transmit signal towards a surface of the product in the tank; receiving an electromagnetic reflection signal resulting from reflection of the transmit signal at the surface of the product; forming a measurement representation based on the transmit signal and the reflection signal, the measurement representation comprising surface echo information indicative of the filling level of the product; adding, to the measurement representation, proof test echo information indicative of a predefined proof test level, resulting in a modified measurement representation; processing the modified measurement representation to determine a proof test level based on the modified measurement representation; and providing a signal indicative of a result of the processing.

Abstract: A method of determining a filling level of a product in a tank using a radar level gauge system comprising a transceiver, an antenna, and processing circuitry, the method comprising the steps of: generating and transmitting a transmit signal; receiving a reflection signal resulting from reflection of the transmit signal; determining based on the transmit signal and the reflection signal, for each surface echo candidate, a first measure indicative of a distance and a second measure indicating a rate-of-change distribution of the distance; assigning one surface echo candidate as most likely to correspond to single reflection of the transmit signal at the surface of the product, based on an evaluation of the second measure for each surface echo candidate; and determining the filling level based on the first measure for the assigned surface echo candidate.

Abstract: A filling level determination system, for determining a filling level of a product in a tank, comprising a measurement unit for arrangement at a measurement position, the measurement unit including a transceiver; and an antenna arrangement coupled to the transceiver for radiating an electromagnetic transmit signal generated by the transceiver from the measurement position towards a target position on the tank wall, and for returning an electromagnetic first reflection signal resulting from reflection of the transmit signal at the target position back towards the transceiver; and processing circuitry coupled to the transceiver of the measurement unit and being configured to determine the filling level based on tank deformation data indicative of a known relation between the level of the product in the tank and deformation of the tank at the first target position, and a timing relation between the first transmit signal and the first reflection signal.

Abstract: A radar level gauge system for determining a topographic property of a product, comprising a transceiver; a signal transfer element coupled to the transceiver and configured to emit an electromagnetic transmit signal from the transceiver in an emission direction; a propagating member for propagating the transmit signal towards the surface of the product and a reflection signal back towards the transceiver, the propagating member being movably arranged in relation to the signal transfer element and configured to deflect the transmit signal; an elastic system coupled to the signal transfer element and to the propagating member, and arranged to define at least one property of an oscillating movement of the propagating member in relation to the signal transfer element; an actuator arranged to initiate the oscillating movement; and processing circuitry coupled to the transceiver for determining the topographic property based on the transmit signal and the reflection signal.

Abstract: A method of detecting leakage, comprising the steps of: performing a sequence of monitoring operations; and providing, when it is determined that leakage is present, a signal indicative of detected leakage. Each monitoring operation includes the steps of: generating a transmit signal exhibiting a time-varying frequency; receiving a reflection signal resulting from reflection of the transmit signal at the surface; forming an intermediate frequency signal for the present monitoring operation based on the transmit signal and the reflection signal; determining a phase of the intermediate frequency signal for the present monitoring operation; determining, based on the phase for the present monitoring operation and the phase associated with at least one previous monitoring operation, a measure indicative of a present rate of change of the phase; comparing the measure with a predefined threshold value; and determining a presence of leakage based on the comparison.

Abstract: The present invention relates to a method of proof-testing a radar level gauge system arranged to determine a filling level of a product in a tank, the method comprising the steps of: transmitting an electromagnetic transmit signal towards a surface of the product in the tank; receiving an electromagnetic reflection signal resulting from reflection of the transmit signal at the surface of the product; forming a measurement representation based on the transmit signal and the reflection signal, the measurement representation comprising surface echo information indicative of the filling level of the product; adding, to the measurement representation, proof test echo information indicative of a predefined proof test level, resulting in a modified measurement representation; processing the modified measurement representation to determine a proof test level based on the modified measurement representation; and providing a signal indicative of a result of the processing.

Abstract: The present invention relates to a radar level gauge for determining a distance (D) to a surface of a product in a tank, said radar level gauge comprising: a transceiver configured to transmit an electromagnetic transmit signal (ST) with varying frequency towards said surface and to receive an electromagnetic return signal (SR), via a signal propagation device; a mixer adapted to mix the transmitted electromagnetic transmit signal with the received electromagnetic return signal to provide a mixer output signal including information about the surface's echo and information about another echo; and processing circuitry configured to apply an algorithm to the mixer output signal, which algorithm provides a distance-level rate matrix wherein the surface's echo and said another echo each is determined in the two dimensions distance and level rate, and to determine the distance to the surface based on the thus determined echo of the surface.

Abstract: A radar level gauge comprising transceiver circuitry configured to obtain a tank signal including a peak representing a surface echo, and at least one peak caused by a ghost echo in a neighborhood of the surface echo. The gauge further includes a tank signal filter receiving the tank signal as input and providing an echo threshold profile, the threshold profile having at least one local maximum substantially coinciding with one of the peaks in the tank signal, and processing circuitry configured to use the echo threshold profile to disregard peaks in the tank signal which are associated with ghost reflections. The filtering of the tank signal thus provides an adaptive threshold, which is aligned with the peak(s) in the tank signal. By using this threshold in the surface echo identification, at least some ghost echoes occurring in the tank signal may be disregarded.

Abstract: A radar level gauge for determining a process variable of product in a tank, having processing circuitry configured to process a tank signal and, when no surface echo can be identified, enter a wait state. The wait state includes a) storing the tank signal in memory, b) obtaining a wait state tank signal, c) comparing the wait state tank signal with the stored tank signal to determine a tank signal difference measure, d) repeating steps b) and c) until the tank signal difference measure is greater than a predefined threshold, e) processing the wait state tank signal to identify a surface echo, and f) when no surface echo can be identified in the wait state tank signal, setting an alarm. By storing the tank signal when the wait state is entered, it is therefore possible to defer an alarm until the tank signal deviates from this stored tank signal.

Abstract: The present invention relates to a radar level gauge for determining a distance (D) to a surface of a product in a tank, said radar level gauge comprising: a transceiver configured to transmit an electromagnetic transmit signal (ST) with varying frequency towards said surface and to receive an electromagnetic return signal (SR), via a signal propagation device; a mixer adapted to mix the transmitted electromagnetic transmit signal with the received electromagnetic return signal to provide a mixer output signal including information about the surface's echo and information about another echo; and processing circuitry configured to apply an algorithm to the mixer output signal, which algorithm provides a distance-level rate matrix wherein the surface's echo and said another echo each is determined in the two dimensions distance and level rate, and to determine the distance to the surface based on the thus determined echo of the surface.

Abstract: A radar level gauge comprising transceiver circuitry configured to obtain a tank signal including a peak representing a surface echo, and at least one peak caused by a ghost echo in a neighborhood of the surface echo. The gauge further includes a tank signal filter receiving the tank signal as input and providing an echo threshold profile, the threshold profile having at least one local maximum substantially coinciding with one of the peaks in the tank signal, and processing circuitry configured to use the echo threshold profile to disregard peaks in the tank signal which are associated with ghost reflections. The filtering of the tank signal thus provides an adaptive threshold, which is aligned with the peak(s) in the tank signal. By using this threshold in the surface echo identification, at least some ghost echoes occurring in the tank signal may be disregarded.

Abstract: A radar level gauge for determining a process variable of product in a tank, having processing circuitry configured to process a tank signal and, when no surface echo can be identified, enter a wait state. The wait state includes a) storing the tank signal in memory, b) obtaining a wait state tank signal, c) comparing the wait state tank signal with the stored tank signal to determine a tank signal difference measure, d) repeating steps b) and c) until the tank signal difference measure is greater than a predefined threshold, e) processing the wait state tank signal to identify a surface echo, and f) when no surface echo can be identified in the wait state tank signal, setting an alarm. By storing the tank signal when the wait state is entered, it is therefore possible to defer an alarm until the tank signal deviates from this stored tank signal.

Abstract: A radar level gauge comprising a physical communication interface bi-directional communication of data structured according to either a first digital communication protocol or a second digital communication protocol, first communication circuitry for communicating measurement data from the field device, second communication circuitry for enabling configuration of the field device, protocol identification circuitry connected to the communication interface for intercepting data and configured to parse intercepted data to identify the digital communication protocol, and control circuitry for directing the intercepted data to one of the first and second communication circuitries based on the identified protocol.

Abstract: A radar level gauge comprising a physical communication interface bi-directional communication of data structured according to either a first digital communication protocol or a second digital communication protocol, first communication circuitry for communicating measurement data from the field device, second communication circuitry for enabling configuration of the field device, protocol identification circuitry connected to the communication interface for intercepting data and configured to parse intercepted data to identify the digital communication protocol, and control circuitry for directing the intercepted data to one of the first and second communication circuitries based on the identified protocol.

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 radar level gauge system comprising a single conductor probe extending through a tubular mounting structure towards and into the product in the tank, a shielding structure radially spaced apart from the single conductor probe and extending along a top portion of the probe inside the mounting structure and past the lower end of the mounting structure, and processing circuitry connected to the transceiver for determining the filling level of the product in the tank. The shielding structure at least partly encloses the top portion of the single conductor probe, and is open in a radial direction to allow entry of the product. The shielding structure exhibits a total enclosing arc angle around the single conductor probe greater than 180° inside the tubular mounting structure, and a total enclosing arc angle around the single conductor probe that decreases with increasing distance from the lower end of the mounting structure.

Abstract: The present invention relates to a radar level gauge system comprising a signal propagation device; a microwave signal source; a microwave signal source controller; a mixer configured to combine a transmit signal from the microwave signal source and a reflection signal from the surface to form an intermediate frequency signal; and processing circuitry coupled to the mixer and configured to determine the filling level based on the intermediate frequency signal. The microwave signal source is configured to exhibit a phase noise greater than or equal to ?70 dBc/Hz @ 100 kHz offset from a carrier frequency for the transmit signal.

Abstract: The present invention relates to a radar level gauge system comprising a signal propagation device; a microwave signal source; a microwave signal source controller; a mixer configured to combine a transmit signal from the microwave signal source and a reflection signal from the surface to form an intermediate frequency signal; and processing circuitry coupled to the mixer and configured to determine the filling level based on the intermediate frequency signal.