Abstract: The invention provides a method for configuring for use a vibrating fork level switch having a dry fork frequency DFF. The method involves establishing a wet fork frequency WFF and combining this with the DFF to configure the switch for use in media of differing densities.

Abstract: A gauging instrument intended to be sealingly mounted on a nozzle of a tank, and comprising an attachment collar intended to mate with said nozzle so as to face the product in the tank, a dielectric filling member with a radially extending collar portion which abuts an outer rim of said attachment collar, and an annular spring element arranged between the outer rim the radially extending collar portion. One or several fastening elements are configured to secure the attachment collar to, and in mating relationship with, the nozzle, such that the radially extending collar portion is sandwiched between the outer rim of the attachment collar and the nozzle, and the annular spring element exerts a contact pressure on the collar portion against the nozzle to thereby ensure a process seal.

Abstract: A radar level gauge comprising transceiver circuitry, a propagation device and processing circuitry for determining a value of the process variable based on a relationship between a transmit signal and a return signal. The gauge has a DC/DC converter connected to a power supply interface, and configured to convert a first voltage to a second voltage, lower than the first voltage, and an energy storage. The gauge further has a switch, connected between the DC/DC converter and the energy storage, the switch having a non-conducting state for disconnecting the energy storage from the DC/DC converter when the transceiver circuitry is active, and a conducting state for connecting the energy storage to the DC/DC converter only when the transceiver circuitry is inactive.

Abstract: A radar level gauge having a wave guiding structure arranged to guide a measurement signal towards the surface and to return the reflected signal, and an electromagnetic wave transducer arranged to emit the measurement signal into the wave guiding structure as electromagnetic waves. The electromagnetic wave transducer has a plurality of radiating elements arranged in N?1 concentric feeder rings, where a radius of each feeder ring coincides with a radial zero of an electrical field of the H0N-mode, and feeding circuitry connected to feed the measurement signals from the transceiver circuitry to the radiating elements, thereby causing the electromagnetic wave transducer to excite electromagnetic waves in the H01-mode. With this choice of feeder ring radii, the H0N mode will not be excited.

Abstract: A method of determining at least a first interface level of a first interface in a tank containing a stratified substance composition, comprising the steps of generating and transmitting an electromagnetic transmit signal; guiding the transmit signal at least partly through the stratified substance composition; returning an electromagnetic reflection signal resulting from reflection of the transmit signal; receiving, the reflection signal; determining, based on the reflection signal and a timing relation between the reflection signal and the transmit signal, an echo signal exhibiting an echo signal strength as a function of a propagation parameter indicative of position along the probe; and determining, the first interface level based on a first propagation parameter value indicative of a first threshold position for which the echo signal has reached a predetermined first threshold signal strength, and a first offset indicative of a first offset distance from the first threshold position.

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 a signal propagation device, a dielectric filling member arranged in the signal propagation device, and a sealing arrangement for preventing tank content from escaping into the outside environment. The dielectric filling member includes a main body formed of a polymer material, and at least one structurally reinforced element formed of a modified polymer material providing, the modified polymer material being obtained by modifying the polymer material with a filler material, wherein the at least one structurally reinforced element is integrally formed with the main body by sintering, and forms part of the sealing arrangement. The present invention is based on the realization that a structurally reinforced element, made of a modified polymer material, may be integrated into the main body by sintering.

Abstract: A radar level gauge system comprising a first transceiver; a second transceiver; an antenna arranged to radiate a first transmit signal generated by the first transceiver and a second transmit signal generated by the second transceiver, and to receive a first reflection signal and a second reflection signal; a tubular waveguide to guide the transmit signals towards the interface, and to guide the reflection signals back towards the antenna; a plurality of signal interacting structures arranged at different levels along a the tubular waveguide, to selectively interact with the second transmit signal to contribute to the second reflection signal; and processing circuitry to determine a level of the interface between liquid phase product and vapor phase product based on a relation between the first transmit signal and the first reflection signal, and a density distribution based on a relation between the second transmit signal and the second reflection signal.

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 gauging arrangement for performing radar level gauging in a tank having a tank wall which is impermeable to a product held in the tank and transmissive to radar signals, comprising an attachment device configured to be secured to a substantially flat portion of said tank wall, without penetration of the tank wall, and a radar level gauge including a directional antenna, the radar level gauge being mounted to the attachment device, such that, when said attachment device is secured against the tank wall, the directional antenna is positioned so as to enable transmission of radar signals through the tank wall. By mounting a radar level gauge to an attachment device which can be secured to the tank wall without penetrating the tank wall, radar level gauging can thus be provided without damaging or interfering with the tank.

Abstract: A radar level gauge system comprising a transceiver; an elongated two-conductor probe having a signal conductor connected to the transceiver, and a rigid shielding conductor spaced apart from the signal conductor by an open space. The two-conductor probe extends from an upper probe end to a lower probe end; and processing circuitry for determining the filling level based on a transmit signal and a surface echo signal. The shielding conductor exhibits an open cross-section profile, in a cross-section with a plane perpendicular to the two-conductor probe, along at least a portion of the two-conductor probe. The two-conductor probe further comprises a plurality of spacer arrangements. Each spacer arrangement includes at least a first spacer member attached to the rigid shielding conductor and arranged between the signal conductor and the rigid shielding conductor for preventing contact between the signal conductor and the shielding conductor.

Abstract: A radar level gauge including a wave guiding structure and a cavity formed inside the wave guiding structure, and a dielectric filling member arranged at least partly within said cavity. The dielectric filling member includes a main body formed of a polymer material, at least one microwave absorbing element formed of a modified polymer material providing a microwave attenuation of at least 1 dB/centimeter at an operating frequency of the radar level gauge, the modified polymer material being obtained by modifying said polymer material with a filler material, wherein the at least one microwave absorbing element is integrally formed with said main body by sintering.

Abstract: A radar level gauge system comprising a transceiver; a multi-conductor probe comprising a first probe conductor and a second probe conductor extending together from an upper probe end to a lower probe end; a plurality of spacer arrangements distributed along the multi-conductor probe; and processing circuitry for determining the filling level. Each spacer arrangement in the plurality of spacer arrangements comprises a first spacer member configured to reflect a transmit signal as a first spacer reflection signal having a first amplitude; and a second spacer member configured to reflect the transmit signal as a second spacer reflection signal having a second amplitude. The first spacer member and the second spacer member are arranged along the multi-conductor probe so that the first and second spacer reflection signals interact to provide a combined spacer reflection signal having an amplitude lower than each of the first amplitude and the second amplitude.

Abstract: A radar level gauge system comprising a transceiver; a probe for guiding a transmit signal towards a product in a tank, and for returning a surface echo signal; processing circuitry for determining the filling level based on the transmit signal and the surface echo signal; and a connection arrangement for conductively connecting the probe to the tank, and for providing the transmit signal from the transceiver to the probe. The connection arrangement comprises a feed-through member to which the probe is conductively connected. The feed-through member is in conductive contact with the tank at a grounding position, and a signal conductor extends through the feed-through member from the outside of the tank to the inside of the tank. A tank coupling arrangement is arranged on the inside of the tank to electrically connect the signal conductor and the metallic portion of the tank.

Abstract: A radar level gauge comprising a directional antenna, a hollow wave guide connected to the antenna, a tank connection having a through hole with an annular abutment, a dielectric filling member arranged in the tank connection, the dielectric filling member comprising an annular collar portion resting against the annular abutment, a clamping member inserted into the tank connection, a fastening member attached to the fixed tank connection to secure the clamping member between the fastening member and the annular abutment, and a spring member arranged between the fastening member and the clamping member. The spring member presses the clamping member towards the annular abutment, to apply a controlled pressure on the annular collar portion, allowing the annular collar portion to serve as a pressure tight sealing between a tank interior and a tank exterior.

Abstract: A radar level gauge comprising a housing enclosing a compartment providing explosion proof protection, RLG circuitry located inside compartment, which circuitry is incompatible with intrinsic safety requirements, and a signal propagation device located outside the compartment. The housing has an explosion proof first signal passage providing a transmission line for the microwave transmit signal, and an explosion proof second signal passage in providing a two-wire interface for electrically conductively connecting the radar level gauge to an intrinsically safe system located externally of the radar level gauge. Further, the RLG includes an electrical barrier connected between the RLG circuitry and the two-wire interface, the electrical barrier preventing energy and/or thermal energy in the RLG circuitry from compromising the intrinsic safety of an intrinsically safe system connected to the two-wire interface.

Abstract: The present invention relates to a field device adapted to determine a process parameter value related to a tank, the field device comprising a terminal block with: a first interface configured to connect to two wires of a loop; a first electrical conductor and a second electrical conductor for connecting the first interface with field device electronics, the second electrical conductor having a voltage drop generating element; a first power supply conductor connected to said second electrical conductor upstream of the voltage drop generating element and a second power supply conductor connected to said second electrical conductor downstream of the voltage drop generating element; and a second, auxiliary interface adapted for wired connection to an external device and configured at least for communication with said external device, wherein the second auxiliary interface comprises a communications connector which is galvanically isolated from the field device electronics.

Abstract: A tank arrangement including a guided wave radar level gauge installed in a tank, and having a single wire transmission line probe extending through a passage through a conducting structure in the tank. Along the section of the probe that extends through the passage, the arrangement comprises a propagation field limiting structure adapted to reduce a propagation field of an electromagnetic signal propagating along the probe. With this design, the radial extension of the propagating field can be locally reduced so that a sufficient portion of the signal power is allowed to pass through the passage.

Abstract: A radar level gauge system, for determining a filling level of a product in a tank. The radar level gauge system includes a transmission line probe arranged inside the tank; a tank feed-through for mechanically attaching the transmission line probe to a tank wall of the tank through a non-conductive mechanical connection between the transmission line probe and the tank wall, and for providing a conductive electrical connection to the transmission line probe from outside the tank; and a measurement electronics unit arranged outside the tank. The measurement electronics unit includes: a transceiver; an electrical filter circuit having an input coupled to the transceiver and an output coupled to the transmission line probe via the tank feed-through, the electrical filter circuit exhibiting a series capacitance for non-conductively coupling the transceiver to the transmission line probe via the tank feed-through; and processing circuitry for determining the filling level.