Optical Sensor With External Medium Placement
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Solution Overview
Problem
Existing sensors for monitoring media with changing refractive indices are prone to measurement errors due to deposits and dirt on the interface or reflection surfaces, which can falsify results.
Innovation Solution
A compact sensor design with a cup-shaped transparent housing containing an electromagnetic radiation source, detector, and mirrors, where the medium is placed outside, allowing for accurate detection of refractive index changes through transmitted light principles, with a photodiode array for precise location determination, independent of radiation intensity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an interface between the body and solution is used for reflection-based detection, then the measurement can be performed, but deposits and dirt on the interface or reflection surface falsify the measurement result
Solution Approach 1:
The patent removes the medium from the housing interior and places it outside, eliminating the harmful interface between the sensor components and the medium. The housing no longer contains the medium, so deposits and dirt cannot form on internal surfaces. The detection is performed through the housing wall where the medium is positioned externally, thereby extracting the harmful contamination path from the measurement system.
Solution Approach 2:
The housing wall acts as an intermediary element that separates the sensor components (inside the housing) from the medium (outside the housing). Light passes through the housing wall to detect refractive index changes in the medium, while the wall itself prevents direct contact between the medium and sensor components, thereby preventing contamination on critical surfaces.
2Reliability
If the medium is placed inside the housing with transparent components, then the sensor can monitor the medium, but the sensor becomes more complex and larger
Solution Approach 1:
The patent extracts the medium from the housing interior and positions it outside the housing. This simplifies the housing structure as it no longer needs to contain the medium, allowing for a more compact and simpler sensor design while maintaining monitoring capability through external placement and light transmission through the housing wall.
Solution Approach 2:
The patent separates the sensor components (housing, radiation source, detector) from the medium, creating distinct functional zones. The housing contains all electronic and optical components, while the medium is positioned externally. This segmentation allows each component to be optimized independently and simplifies the overall structure compared to integrating the medium within the housing.
3Measurement precision
If radiation intensity is used for detection, then the measurement can be performed, but aging processes in the radiation source and detector affect the sensor
Solution Approach 1:
The patent changes the detection parameter from radiation intensity to the position of the radiation spot on the detector array. By detecting the spatial position of the focused light spot rather than its intensity, the sensor becomes independent of aging effects in the radiation source and detector, as position detection does not suffer from the same degradation mechanisms as intensity measurement.
Solution Approach 2:
The patent replaces intensity-based detection with position-based detection using a photodiode array. Instead of measuring the intensity of radiation (which is affected by aging), the system measures the spatial position of the radiation spot, substituting a measurement method that is inherently more stable and less susceptible to aging effects over time.
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
The sensor effectively monitors medium changes without being affected by contamination or components clouding the medium, ensuring accurate detection of refractive index shifts and substance concentrations, providing a reliable and compact monitoring solution.
Implementation Method 1
the refraction changing when the medium changes
Implementation Method 2
The detector consists of photodiodes arranged in a row or in a matrix, so that the location of the electromagnetic radiation reaching the detector can be detected from the position of the photodiodes
Data Source
Figure 1~2
AI summary
The invention relates to sensors for monitoring a medium, comprising an electromagnetic radiation source and a detector of electromagnetic radiation, the medium being located in the ray path between the electromagnetic radiation source and the detector and the refraction varying when the medium varies. The sensors are characterized by their ease of production. To that end, the electromagnetic radiation source and detector are disposed in at least one housing. Furthermore, either at least one region or at least one component of the housing consists of material which is transparent to electromagnetic radiation, the medium being located in the region or at the component of the housing. At least one wall of the region is so disposed or designed that the radiation for refraction impinges on or emerges from the surface at an angle which is different from 90°. In addition, the detector is at least one photo diode, such that, when the medium varies, the radiation either does not impinge or impinges on the photo diode.