Optical Fluid Level Sensor Using Light Speed Calculation
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Solution Overview
Problem
Conventional fluid level and quality sensors for SCR systems face accuracy and robustness issues, with labor-intensive and costly assembly, and require separate components for level and quality measurement.
Innovation Solution
A sensor system utilizing the speed of light to determine fluid level and quality by calculating the speed of light passing through the fluid and air, using a light emitting unit, a light receiving unit, and a control and evaluation unit, with optional reflectors to enhance accuracy and compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If conventional reed switches and magnetic floats are used for level measurement, then the system can measure fluid level, but the assembly is labor-intensive and costly
Solution Approach 1:
The patent combines multiple separate sensor components (reed switches, magnetic floats, temperature sensors, ultrasound sensors) into a single integrated sensor unit with a common evaluation unit. This merging eliminates the need for separate assemblies, reducing labor-intensive manual assembly and lowering manufacturing costs while maintaining measurement precision for fluid level and other parameters.
Solution Approach 2:
The sensor unit is designed as a multi-functional device that can simultaneously measure fluid level, temperature, and other fluid properties using a single integrated system. The evaluation unit processes multiple sensor inputs (magnetic, thermal, acoustic) through one unified interface, eliminating the need for separate measurement systems and reducing overall assembly complexity.
2Adaptability or versatility
If separate components are used for level and quality measurement, then comprehensive fluid monitoring is achieved, but device complexity increases
Solution Approach 1:
The patent integrates level measurement (magnetic float), temperature measurement (temperature sensor), and quality measurement (ultrasound sensor) into a single sensor unit that shares a common evaluation unit. This consolidation maintains comprehensive fluid monitoring capability while reducing device complexity by eliminating redundant structural elements and simplifying the overall system architecture.
Solution Approach 2:
The evaluation unit is designed as a universal processor that handles multiple sensor types (magnetic, thermal, acoustic) through a single interface. This multi-functional evaluation unit consolidates what would otherwise require separate processing systems, reducing device complexity while maintaining the ability to monitor all fluid properties comprehensively.
3Measurement precision
If sensors are exposed to aggressive fluids for measurement, then direct measurement is achieved, but sensor reliability decreases
Solution Approach 1:
The patent introduces a magnetic coupling mechanism as an intermediary between the external magnetic field generator and the internal reed switches. This intermediary allows the reed switches to remain protected inside the sensor housing while still achieving accurate level measurement through magnetic field interaction, eliminating direct exposure to aggressive fluids while maintaining measurement precision.
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 solution provides accurate and reliable measurements with a contactless, electromagnetic interference-resistant method, allowing simultaneous level and quality measurement without exposing sensitive components to aggressive fluids, and is cost-effective and robust.
Implementation Method 1
calculating a speed of light of the light when passing the radiation path
Implementation Method 2
at least one light reflecting unit that is arranged in the radiation path for reflecting said emitted light
Data Source
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AI summary
The present invention relates to a sensor system and to a method for measuring a fluid level and/or a fluid quality. For instance, such a sensor system can be used with a urea tank in a selective catalytic reduction (SCR) system for purification of harmful NOx components in the exhaust gases of diesel vehicles. A sensor system (100) for measuring a fluid level and/or a fluid quality, the sensor system comprises at least one light emitting unit (120) that is arranged for emitting light in a first direction into a container (114) containing said fluid, at least one light receiving unit (128) that is arranged for detecting said emitted light after it has passed a radiation path (118) which is at least partly arranged in the container, at least one light reflecting unit (112, 124) that is arranged in the radiation path for reflecting said emitted light, and a control and evaluation unit (130), which is operable to calculate a speed of light of the light when passing the radiation path and to determine the fluid level and/or the fluid quality from the calculated speed of light.