Saab Rosemount Tank Radar Ab

Saab Marine Electronics Ab

Saab Marine Electronics Aktiebolag

St. Jude Medical Ab

Saab-scania Ab

Rosemount Tank Radar Ab

Kurt Olov Edvardsson

Anders Jirskog

Magnus Ohlsson

Jan Westerling

An implantable medical device has a conductive housing, electronic circuitry for the operation of the implantable medical device, and radio frequency circuitry for transmitting and/or receiving radio frequency signals, the electronic circuitry and the radio frequency circuitry being interconnected and arranged within in the housing. The housing has at least one slot therein, and a slot feed operatively interconnected between the radio frequency circuitry and the slot. The electrically conductive housing provided with the at least one slot is operable as an antenna for the radio frequency signals. The electric circuitry, the radio frequency circuitry, and the interconnection can be enclosed by the housing so that they are shielded from external radiation in any direction.

Implantable medical device with slotted housing serving as an antenna

The present invention relates to a radar level gauge () comprising an antenna (), a tank sealing (), an electronics unit () and a waveguide feed () between the electronics unit () and the antenna (). The waveguide () is essentially straight and has a 90&#xb0;-symmetric cross section and is further arranged to accommodate two essentially orthogonal waveguide modes. The waveguide () further has a length (I) below two times the range resolution of said radar level gauge (). The present invention further relates to a method for improved radar level gauging using a radar level gauge () as above.

Radar level gauge with antenna arrangement for improved radar level gauging

There is provided a radar level gauge using microwaves for measuring a level of a surface of a product in a tank, comprising an antenna for transmitting microwaves to the surface and receiving microwaves reflected by the surface, a measurement circuitry feeding said antenna through a hollow wave guide and said wave guide including at least an antenna wave guide member, at one end couplable to the antenna and at its other end having an opening in an intersection across the wave guide, wherein the radar level gauge further comprises: a dielectric barrier extending along said intersection across the opening of said antenna wave guide member for non-conductively separating said antenna wave guide member from the measurement circuitry, said dielectric barrier having a first side facing the wave guide in a direction towards the antenna wave guide member and said dielectric barrier having a second side facing a direction substantially away from said antenna wave guide member.

Method and an apparatus for insulation of a radar level gauge

An apparatus for gauging the level of a liquid, above which a gas having a dielectric constant within a predetermined dielectric constant range exists, comprises a transmitter for transmitting a microwave signal in a propagation mode in a tube through the gas towards the liquid surface; a receiver for receiving the microwave signal reflected against the liquid surface and propagating back through the tube; and a processing device for calculating from the propagation time of the transmitted and reflected microwave signal the level of the liquid. In order to essentially avoid the influence on the calculated level by the dielectric constant of the gas above the liquid, the transmitter is adapted to transmit the microwave signal in a frequency band, at which the group velocity of the microwave signal in the propagation mode in the tube is, within the predetermined dielectric constant range, essentially independent of the dielectric constant.

Apparatus and method for radar-based level gauging

An antenna device in a radar-based level gauge mounted at an opening in a roof of a tank, the antenna device comprising at least one elongated radiating structure, which has a length that is substantially larger, preferably more than 3-5 times longer, than a maximum cross-sectional length dimension of the opening; is oriented in a non-vertical position; and is configured and fed to produce an essentially vertical radiation beam directed downwards in the tank. Preferably, the antenna device is foldable and is inserted into the tank through the opening and oriented in the non-vertical position by means of folding the radiating structure.

Antenna device for radar-based level gauging

The invention relates to a pressure sealing device and a method for decreasing the cut-off frequency in such a pressure sealing device used in a radar level gauging system for gauging a filling level of a product kept in a container, the sealing device comprises a waveguide for feeding microwaves in at least one of the following mode types: transverse electric mode, transverse magnetic mode or hybrid mode. Said waveguide is sealed by a dielectric material. A center conductor is arranged at least partially within said dielectric material.

Device and method in a level gauging system

A bottom reflector for a radar-based level gauge, which measures a level of a liquid stored in a tank by means of transmitting a microwave signal towards the surface of the liquid from the top of the tank, receiving the microwave signal as reflected against the surface of the liquid, and calculating the level of the liquid from the propagation time of the transmitted and reflected microwave signal, wherein the bottom reflector is adapted to be mounted close to the bottom of the tank and comprises a reflecting structure having a first reflection coefficient for the microwave signal when the level of the liquid is above the reflecting structure and a second reflection coefficient for the microwave signal when the level of the liquid is below the reflecting structure, wherein the first reflection coefficient is substantially lower than the second reflection coefficient.

Bottom reflector for a radar-based level gauge

A method for radar-based gauging of the level of a substance in a tank ( ) having at least one interfering structure, e.g. a beam ( ); an agitator ( ) or a tank side wall ( ), comprises transmitting a microwave signal in a predetermined polarization state (LHCP) towards the surface ( ) of the substance and the at least one interfering structure; detecting, separately in two different polarization states (LHCP, RHCP), microwave signals ( ) as reflected against the surface of the substance and against the at least one interfering structure; distinguishing based on signal strengths of the microwave signals detected separately in the two different polarization states, the detected microwave signal ( ), which has been reflected against the surface of the substance; and calculating based on a propagation time of the distinguished microwave signal the level of the substance in the tank.

Method and apparatus for radar-based level gauging

A method for radar-based gauging of the level of a substance in a tank ( ) having at least one interfering structure ( ), comprises the steps of: (i) transmitting a microwave signal in a plurality of radiation lobes ( ; ), each of which being individually directed towards the substance and at least one of which being directed towards the interfering structure; (ii) for each of the radiation lobes detecting temporally resolved the microwave signal as reflected against the substance, and for at least one of the lobes detecting the microwave signal as reflected against the interfering structure; (iii) based on signal strengths of the detected microwave signals, distinguishing the detected microwave signals, which have been reflected against the substance; and (iv) based on a propagation time of at least one of the microwave signals distinguished as those, which have been reflected against the substance, calculating the level of the substance.

A device for gauging the level of a fluid in a container includes a floating roof, a transmitter for feeding a first microwave signal downwards in the direction of a fluid surface of the fluid, and a receiver for receiving a reflected microwave signal. The device includes a collector located above and in the vicinity of the floating roof, collecting the first microwave signal producing a collected microwave signal. The device also includes a vertical wave guide passing through the floating roof. The vertical wave guide guides the collected microwave signal to the fluid surface, and receives a reflected microwave signal reflected from the fluid surface. The vertical wave guide then guides the reflected microwave signal back to the collector and further to the receiver. It is a special feature to permit accurate measurement of the level of the fluid surface without having direct access to the surface.

Method and apparatus for level gauging using radar in floating roof tanks

Device for gauging the level of a fluid

A device in storage tanks with a floating roof and a vertical stillpipe with a number of openings distributed along the length of the same for reducing the outflow of volatile substances from stored products is described. The device comprises a floating body with at least one peripheral seal engaging the inner circumference of the stillpipe. The volume/weight relationship of the floating body is such that it floats in the product and encloses the product surface within its periphery. The floating body is designed so that the gas pressure inside the body is the same as the gas pressure within the stillpipe above the floating body. The body is so constructed that direct gauging with microwaves may be performed against the product surface through the inside of said stillpipe.

Stillpipe sealing device

Device at a radar level gauge

Device for level gauging with microwaves

The invention concerns a method and an apparatus for measuring the level of a material with microwave signals. The apparatus consists of a signal processing unit (10) and a transmitter unit (1) of known type. The transmitter unit produces a measuring signal having a frequency (f.sub.m) corresponding to the distance (H) to be measured and a reference signal having a frequency (f.sub.r) corresponding to an accurately known length (L). In the signal processing unit (10) the reference signal is multiplied by a selectable number (AQ) which is proportional to the quotient of an assumed value for the distance divided by the known length (L), after which the frequency is divided by a fixed number (Z) so that the frequency of the signal after multiplication and division becomes equal to the expected frequency of the measuring signal. Thereafter the control signal thus produced is mixed with the measuring signal, for determination of the phase difference between them, which is sampled in each of a succession of regular sampling intervals, and the change in phase difference through the successive sampling intervals is calculated for determining a correction term for the assumed distance.

Growing community of inventors

Täby, Sweden

Kurt Olov Edvardsson