Guided Wave Radar Probe Field Limiting Structure
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Solution Overview
Problem
Radar level gauges with single wire transmission line probes face performance issues when passing through narrow electrically conducting structures, leading to signal power loss and interference due to the radial extension of the electromagnetic signal field, which conventional solutions like PTFE coating address but at the cost of increased expense and resistive losses.
Innovation Solution
A tank arrangement with a guided wave radar level gauge featuring a single wire transmission line probe divided into sections, where a propagation field limiting structure is applied only to the section passing through the narrow passage, reducing the radial extension of the signal field and maintaining signal strength by slowing down wave propagation, ensuring at least 95% of the signal power passes through.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single wire transmission line probe is used without coating, then the probe structure is simpler and cheaper, but signal power is significantly reduced when passing through narrow passages in electrically conducting structures
Solution Approach 1:
The patent applies a dielectric coating only to the specific section of the probe that passes through the narrow passage in the electrically conducting structure, rather than coating the entire probe. This localized application reduces the radial extension of the electromagnetic field precisely where needed (through the passage), minimizing signal power loss, while leaving other sections uncoated to maintain manufacturing simplicity and reduce overall cost.
2Object-affected harmful factors
If the probe is coated with PTFE to reduce radial extension of the propagation field, then signal interference is reduced, but resistive losses increase leading to weaker echo from the product surface
Solution Approach 1:
The dielectric coating is applied locally only to the passage-section of the probe where electromagnetic field interference from electrically conducting structures occurs. This localized approach reduces harmful interference precisely where the probe interacts with the conducting structure, while avoiding coating on other sections would prevent unnecessary resistive losses that would weaken the echo signal from the product surface.
Solution Approach 2:
Instead of applying a complete coating along the entire probe length, the patent uses partial action by coating only the specific section that passes through the narrow passage. This partial application provides sufficient interference reduction for the critical area without the excessive energy loss that would result from full-length coating.
3Object-affected harmful factors
If a propagation field limiting structure is applied to the entire probe, then signal interference is minimized throughout, but manufacturing cost and complexity increase significantly
Solution Approach 1:
The propagation field limiting dielectric coating is applied exclusively to the specific section of the probe that passes through the narrow passage in the electrically conducting structure. This localized application addresses interference only where it occurs, rather than applying a complex limiting structure to the entire probe, thereby minimizing both interference and structural complexity.
Solution Approach 2:
The probe is divided into distinct sections: uncoated sections above and below the passage, and a coated section through the passage. This segmentation allows the propagation field limiting structure to be applied only where necessary, reducing overall device complexity while still providing interference protection in the critical area.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This design effectively reduces signal loss and interference while maintaining measurement accuracy, allowing the level gauge to operate satisfactorily through narrow passages with minimal impact on other probe sections, thus enhancing the reliability and cost-effectiveness of the system.
Implementation Method 1
a propagation field of an electromagnetic signal in the operating frequency range propagating along the third section of the probe to have a second radial extension, wherein the second radial extension is smaller than the first radial extension
Implementation Method 2
a single wire transmission line probe connected to the transceiver circuitry and extending into the tank through a tank entry and configured to guide the electromagnetic transmit signal from the transceiver circuitry to a surface of the product
Implementation Method 3
The electromagnetic signals are subsequently reflected at the surface of the product, and the reflected signals are received by a receiver or transceiver comprised in the radar level gauge system
Data Source
AI summary
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.