Scatterometer Calibration Diaphragm for Diffuse Radiation Control
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Solution Overview
Problem
Existing scattered light measuring devices face saturation issues due to excessive diffuse scattered radiation, which interferes with the detection of scattered radiation by light sensors, making it difficult to accurately calibrate the devices for different particle concentrations.
Innovation Solution
A calibration device with a scattering body positioned within the measuring chamber, featuring a carrier with a pin design and a diffuser with a diaphragm opening, reduces the impact of diffuse scattered radiation by using a scattering layer and additional diffusers to control the intensity of scattered light reaching the sensors.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a scattering body is inserted into the measuring chamber to simulate particle concentrations, then calibration capability is improved, but diffuse scattered radiation increases causing light sensor saturation
Solution Approach 1:
A diaphragm with a restricted opening is introduced as an intermediary element between the scattering body and the light sensors. This diaphragm selectively transmits scattered light while blocking diffuse scattered radiation, thereby mediating the interaction between the scattering body and sensors to prevent saturation while maintaining calibration functionality
Solution Approach 2:
The diaphragm creates a localized light path restriction, allowing only light from specific directions (scattered light from the beam path) to reach the sensors while blocking light from other directions (diffuse scattered radiation). This local quality control enables selective transmission of useful light while excluding harmful radiation
2Measurement precision
If the light beam intensity is increased to improve measurement sensitivity, then detection precision is improved, but diffuse scattered radiation increases causing sensor saturation
Solution Approach 1:
The diaphragm acts as a mediator that allows high-intensity light beams to be used for improved detection precision while preventing the associated diffuse scattered radiation from saturating the sensors. The diaphragm selectively transmits the useful scattered light signal while blocking the harmful diffuse radiation
Solution Approach 2:
By restricting the light path through the diaphragm opening, the system allows high-intensity illumination for better precision while locally controlling which light paths reach the sensors, excluding the harmful diffuse scattered radiation that would otherwise cause saturation
3Object-affected harmful factors
If a diffuser is used to reduce diffuse scattered radiation, then harmful radiation is reduced, but light transmission to sensors is blocked
Solution Approach 1:
Instead of using a diffuser that uniformly reduces all light, the solution segments the light paths by using a diaphragm with a specific opening that selectively transmits only scattered light from the beam path while blocking diffuse scattered radiation from other directions, thereby maintaining light transmission while reducing harmful radiation
Solution Approach 2:
The diaphragm opening provides local quality control by allowing light transmission only from specific directions (where scattered light originates) while blocking light from other directions (where diffuse scattered radiation originates), thus maintaining necessary illumination while reducing harmful radiation
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 effectively reduces the influence of diffuse scattered radiation, allowing for precise calibration of scattered light measuring devices by regulating the intensity of scattered light emitted by the scattering body, enabling accurate measurement of exhaust gas values with varying particle concentrations.
Implementation Method 1
a scattering body is inserted into the measuring chamber, which emits scattered light with a defined intensity and distribution when irradiated with the light from the light source
Implementation Method 2
a diffuser with a restricted opening is provided to dampen the scattered radiation or to dampen the light output
Data Source
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AI summary
The invention relates to a calibration device (30) for calibrating a scatterometer, which is used in particular for measuring a particle concentration in exhaust gases of motor vehicles. The calibration device (30) has at least one scattering member (34), which emits scattered light (20'a, 20'b) with a defined intensity and distribution upon irradiation with a light beam (17a), said scattering member (34) having an emission surface (35) for the scattered light with which at least one light sensor (15a, 15b) for detecting the scattered light (20'a, 20'b) exiting at the emission surface (35) is associated. A screen member (37) having at least one screen opening (38), through which the scattered light (20'a, 20'b) exits in the direction of the at least one light sensor (15a, 15b), is associated with the emission surface (35) of the scattering member (34).