Single Conductor Probe Guided Wave Radar System with Reduced Reflection at the Tip of the Mouth

Abstract

A single conductor probe guided wave radar system with reduced reflections at the tip of a nozzle is disclosed. A radar level gauge system for determining the level of a product in a tank comprising: a transceiver arranged outside the tank for generating, transmitting and receiving electromagnetic signals; a feedthrough arranged inside the tank and via the top of the mouthpiece of the tank A single-conductor probe electrically connected to the transceiver, which passes through the mouthpiece and protrudes into the product, and is used to transfer the transmit signal from the transceiver (S T ) to the surface of the product and return to the transceiver the surface reflection S T The generated surface echo signal (S R ); an impedance matching device provided to the probe extending along a portion of the probe. The width of the impedance matching device in the direction perpendicular to the probe is constant inside the mouthpiece or changes at a first rate of change as the distance to the feedthrough increases, while under the mouthpiece, between S T The distance corresponding to at least one-quarter of the wavelength of , changes at a second rate of change that is negative and more negative than the first rate of change as the distance from the feedthrough increases.

Description

technical field [0001] The invention relates to a GWR (Guided Wave Radar) type radar level gauge system for determining the fill level of a product contained in a tank. Background technique [0002] Radar level gauge (RLG) systems are widely used to determine the fill level of product contained in tanks. Radar level gauging is generally performed by means of non-contact measurement, which emits an electromagnetic signal towards the product contained in the tank, or contact measurement, commonly known as Guided Wave Radar (GWR), which relies on Probes guide and guide electromagnetic signals into the product. The probes are generally arranged to extend vertically from the top of the tank to the bottom of the tank. The probe can also be arranged in a measuring tube, the so-called cavity, which is connected to the outer wall of the tank and fluidly connected to the inside of the tank. [0003] The transmitted electromagnetic signal is reflected at the surface of the product a...

AI Technical Summary

Problems solved by technology

There will therefore only be a large impedance step, but since this impedance step is positioned below the spout end, the area of ​​the tank top where reliable fill height measurements cannot be made (the so-called "dead zone") will start at the end of the mouthpiece and will still be evident

Additionally, there will still be significant signal loss, which limits the maximum measurable distance

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