Rosemount Tank Radar Ab

Håkan Delin

Leif Nilsson

Urban Blomberg

Håkan Nyberg

Lars-Ove Larsson

Lars Ove Larsson

Olov Edvardsson

Stig Larsson

Pär Abrahamsson

Håkan Samor

Peter Schachinger

Carl-Johan Roos

Per Karlsson

Thomas Örtenberg

Leif Nilson

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.

Leakage detection system and method

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.

Non-intrusive contactless filling level determination system and method

Method and system for detecting a cleaning process in a radar level gauge configured to determine a fill level of a product contained in a tank, the radar level gauge comprising a transceiver configured to provide a transmit signal, S, to be propagated towards the product by a propagating device, to receive a reflected signal, S, resulting from a reflection of the transmit signal at a surface of the product, and to determine a fill level in the tank based on the received reflected signal, wherein the method comprises: at a measurement position above the fill level and a known distance from a reference position near a ceiling of the tank, determining a difference in signal amplitude between at least two different fill level measurements; and if the determined difference in signal amplitude exceeds a predetermined threshold value, determining that a cleaning process is ongoing in the tank.

Radar level gauge and method for detecting a cleaning process using the radar level gauge

A radar level gauge system comprising a transceiver; a signal propagation arrangement power monitoring circuitry for determining a presently available power for operation of the radar level gauge system; and processing circuitry coupled to the transceiver and to the power monitoring circuitry, and configured to: acquire a measure indicative of the presently available power for operation of the radar level gauge system from the power monitoring circuitry; perform a set of measurement operations dependent on the presently available power for operation of the radar level gauge system, each measurement operation including controlling the transceiver to generate and transmit an electromagnetic transmit signal, to receive an electromagnetic reflection signal, and to form a measurement signal indicative of a timing relation between the transmit signal and the reflection signal; and determine the filling level based on the measurement signal formed in each of the measurement operations in the set of measurement operations.

Radar level gauging with power-dependent number of measurement operations

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 (S) with varying frequency towards said surface and to receive an electromagnetic return signal (S), 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.

Radar level gauge

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.

Adaptive echo threshold

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.

Radar level gauging with wait state

The present invention relates to a method of controlling a pulsed radar level gauge system, comprising the steps of: acquiring a signal indicative of a present operating temperature; determining an initial frequency control parameter for control of at least one of transmission signal generating circuitry and reference signal generating circuitry based on the present operating temperature and a plurality of data sets each comprising data indicative of a previous operating temperature and a previously determined frequency control parameter for the previous operating temperature; and controlling, starting from the initial frequency control parameter, at least one of the transmission signal generating circuitry and the reference signal generating circuitry to achieve the known frequency difference between the first pulse repetition frequency and the second pulse repetition frequency at the present operating temperature.

Pulsed level gauge system with temperature-based control of pulse repetition frequency

A method for powering a radar level gauge, comprising an initial frequency stabilization procedure, ensuring a stable separation frequency between a first and a second clock frequencies, during which frequency stabilization procedure said radar level gauge is not powered to provide a level output, and a subsequent measurement cycle, performed only when a stable separation frequency has been established, during which said radar level gauge is powered to provide a level output. The present invention allows a radar level gauge system to save power by not providing power to and operating the radar level gauge circuit during such times when the frequency separation would not enable the radar level gauge to provide proper level measurements.

Pulsed radar level gauging with efficient start-up

The present invention relates to a pulsed level gauge system comprising frequency control circuitry. If an acquired signal indicates that the time between the previous filling level determination and the present filling level determination is shorter than a predefined time, the frequency control circuitry controls at least one of a transmit signal generating circuitry and a reference signal generating circuitry comprised in the pulsed level gauge system using previous frequency control settings stored in memory. If the acquired signal indicates that the time between the previous filling level determination and the present filling level determination is longer than the predefined time, the frequency control circuitry iteratively regulates at least one of the transmit signal generating circuitry and the reference signal generating circuitry towards achieving a desired pulse repetition frequency difference between the pulse repetition frequency of the transmit signal and the pulse repetition frequency of the reference signal.

Pulsed level gauge system and method

A method of determining a filling level of a product contained in a tank using a level gauge system, comprising the steps of: transmitting a first signal towards a surface of the product; receiving a first echo signal; determining a present echo characteristic value based on the first echo signal; and comparing the present echo characteristic value and a stored echo characteristic value. If a difference between the present echo characteristic value and the stored echo characteristic value is greater than a predefined value, the method further comprises transmitting at least a second transmit signal towards the surface; receiving at least a second echo signal; and determining the filling level based on the at least second electromagnetic echo signal.

Intermittent filling level determination with dynamically determined number of measurements

The present invention relates to a method comprising providing an activation signal from a wireless communication unit to a measurement unit to switch the measurement unit from its inactive state to its active state; providing a measurement request signal to the measurement unit to request measurement of a filling level of a product in a tank; and thereafter switching the wireless communication unit from its active state to its inactive state. The measurement unit measures the filling level and provides a measurement ready signal to the wireless communication unit; the wireless communication unit is switched from its inactive state to its active state in response to the measurement ready signal received from the measurement unit; the wireless communication unit retrieves the value indicative of the filling level from the measurement unit; and wirelessly transmits the value indicative of the filling level to the remote device.

Battery-powered level gauge system adapted for wireless communication

The method comprises the steps of generating a transmission signal; propagating the transmission signal towards the product; receiving a reflected signal; providing a reference signal exhibiting a time-varying phase difference in relation to the transmission signal; forming a measurement signal; and determining the filling level based on the measurement signal. The method further comprises the steps of: determining a reduced time period comprising a time when the time-varying phase difference corresponds to an anticipated filling level, the reduced time period being shorter than the measurement sweep time period; controlling the level gauge system to change from a low-power state to a high-power state at a start of the reduced time period; and controlling the level gauge system to change back from the high-power state to the low-power state at an end of the reduced time period.

Pulsed level gauge system with adaptive transceiver control

A method of determining a filling level of a product contained in a tank, the method comprising generating and transmitting electromagnetic signals; propagating the transmitted electromagnetic signals towards a surface of the product contained in the tank; receiving echo signals resulting from reflections at impedance transitions encountered by the transmitted electromagnetic signals, including a surface echo signal resulting from reflection at a surface of the product; determining a position of a reference impedance transition using a reference echo signal resulting from reflection of the transmitted electromagnetic signals at the reference impedance transition; determining an update level located above the surface, based on the determined position of the reference impedance transition and a known position of the reference impedance transition; determining a disturbance echo profile using at least one of the echo signals resulting from reflection of the transmitted signals at at least one impedance transition located above the update level; and determining the filling level based on the received echo signals and the disturbance echo profile.

Method of determining a disturbance echo profile for a radar level gauge system

A method for determination of a filling level of a product contained in a tank, comprising the steps of generating and transmitting an electromagnetic signal; propagating the transmitted electromagnetic signal towards the product in the tank; receiving echo signals resulting from reflections at impedance transitions encountered by the transmitted electromagnetic signal; classifying one of the echo signals as a surface echo signal resulting from reflection at a surface of the product inside the tank; evaluating an additional echo signal; providing, if an amplitude of the additional echo signal is greater than a predetermined disturbance echo threshold, a signal indicative thereof; and determining the filling level based on the surface echo signal.

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Linköping, Sweden

Håkan Delin