Radar level gauge with dielectric rod connection

摘要

A radar level gauge using electromagnetic signals to determine a filling level of a product in a tank, comprising an electronics unit including transceiver circuitry, a signal propagation device, and a directional coupler. The gauge further comprises a wave guiding structure comprising a rod of a dielectric material. A mounting portion of the electronics unit defines an opening and is detachably mountable on the dielectric rod so that the rod extends through the opening and is at least partly surrounded by the opening. The mounting portion is further arranged to secure the circuitry portion relative the rod so that the directional coupler is in a position to couple signals between the transceiver circuitry and the rod.;The radar level gauge according to the present invention facilitates replacement of an electronics unit, e.g. in case of malfunction or upgrades. At the same time, the dielectric rod enables a very simple, cost-effective and reliable feeding to and from each electronics unit.

主权项

1. A radar level gauge using electromagnetic signals to determine a filling level of a product in a tank, comprising:
first electronics unit comprising a first mounting portion and a first circuitry portion, said first circuitry portion including first transceiver circuitry for transmitting and receiving electromagnetic signals, first processing circuitry connected to said transceiver circuitry and adapted to determine said filling level based on a relation between transmitted and received signals, and a first directional coupler; a second electronics unit comprising a second mounting portion and a second circuitry portion, said circuitry portion including second transceiver circuitry for transmitting and receiving electromagnetic signals, second processing circuitry connected to said transceiver circuitry and adapted to determine said filing level based on a relation between transmitted and received signals, and a second directional coupler; wherein each electronics unit provides a functionally independent measurement channel; a signal propagation device arranged to direct electromagnetic signals into said tank and to return electromagnetic signals reflected from said tank; and a wave guiding structure arranged to guide said electromagnetic signals between said first and second electronics unit and said signal propagation device, said wave guiding structure comprising a rod of a dielectric material, a portion of said dielectric rod extending outside side tank, wherein each electronics unit is detachably mounted on said dielectric rod, said dielectric rod extending through an opening in said first mounting portion so as to be completely surrounded by said first mounting portion, and said dielectric rod extending through an opening in said second mounting portion so as to be completely surrounded by said second mounting portion, wherein said first and second electronics units are arranged axially separated along said dielectric rod, and wherein said first mounting portion is arranged to secure said first circuitry portion relative said dielectric rod so that said first directional coupler is in a position to couple signals between said first transceiver circuitry and said dielectric rod, and wherein said second mounting portion is arranged to secure said second circuitry portion relative said dielectric rod so that said second directional coupler is in a position to couple signals between said second transceiver circuitry and said dielectric rod.