Optical Sensor for Particulate Concentration Measurement
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Solution Overview
Problem
Existing methods for measuring particulate concentrations in containers are limited by the need for sample dilution, contamination risk, and inability to accurately measure in atypical environments or shallow samples without interrupting vessel agitation.
Innovation Solution
An optical sensor system that non-invasively measures particulate concentrations by directing light through the container wall, using light sources and detectors to detect scattered light, with features like position sensing and calibration methods to ensure accurate readings across various container types and conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If light sources and detectors are positioned to measure through container walls, then non-invasive measurement is achieved, but measurement precision is reduced due to light scattering and absorption by the medium
Solution Approach 1:
The patent changes the wavelength parameter of light to match the absorption characteristics of the medium. By selecting wavelengths that are substantially absorbed by the medium (e.g., infrared wavelengths for water-based media), the measurement is confined to a restricted volume near the container wall, reducing interference from distant particles and improving measurement precision while maintaining non-invasive operation.
2Measurement precision
If multiple source-detector pairs are used to extend measurement range, then device complexity increases, but measurement capability is improved
Solution Approach 1:
The patent divides the measurement system into multiple source-detector pairs, each responsible for a specific segment of the particle concentration range. Each pair is optimized for a particular range, and their responses are combined to achieve a wide linear measurement range, thereby managing device complexity through functional segmentation.
Solution Approach 2:
The patent designs the sensor system to perform multiple functions using the same basic components. The same source-detector pairs are used for both determining particle concentration and determining optical density, allowing a single device to provide multiple measurement capabilities without proportionally increasing complexity.
3Measurement precision
If light wavelength is selected to be absorbed by the medium, then measurement volume is restricted to improve accuracy, but measurement range is reduced
Solution Approach 1:
The patent transitions from measuring a large three-dimensional volume to measuring a restricted region near the container wall by using light wavelengths absorbed by the medium. This dimensional restriction enables precise local measurements, which can then be combined through multiple sensor positions to achieve comprehensive coverage of the entire sample volume.
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
Enables rapid, accurate, and sensitive measurement of particulate concentrations without sample dilution, reducing contamination risk and allowing measurements in small volumes and atypical environments, with low sensitivity to ambient lighting and temperature changes.
Implementation Method 1
The one or more light sources are directed through the vessel wall into the medium, scattered by the particulate matter
Implementation Method 2
The light sources and detectors are selected to emit and detect light in a spectral region that is substantially absorbed by the medium, thereby confining the measurement to a restricted volume within the medium
Implementation Method 3
Measurements of particle concentration are made, e.g., through the wall of the container by detection of back-scattered light
Data Source
AI summary
This invention provides methods and devices to measure particle suspension concentrations through the side wall of a container. Particle back-scatter readings are taken at light wavelengths that do not travel far through the medium. Detected scatter is related to actual particle concentration or standard O.D. values. The methods and devices allow particle concentration readings through containers not normally intended for use in such assays.