Alcohol Content Determination Using Multi-Wavelength IR Absorption
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for spectroscopic determination of alcohol concentration, particularly ethanol, in liquid samples are limited by inaccuracy and restricted to low alcohol content ranges due to overlapping absorption bands in near-infrared spectroscopy, making it difficult to measure in beverages with higher alcohol content and challenging to account for third-party substances.
Innovation Solution
A method using IR light absorption at two or three different wavelengths, specifically around 1200 nm, 1300 nm, and 1450 nm, with cheap LEDs and a detector, allowing for simple, cost-effective, and accurate determination of ethanol concentration without the need for complex equipment like monochromators or precise temperature control, enabling handheld devices for easy use and calibration.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If measurements are carried out at a single wavelength in the near infrared range where water absorption outweighs alcohol absorption, then the measurement can be performed with simple hardware, but the determination of alcohol content becomes inaccurate and is limited to low alcohol contents
Solution Approach 1:
The patent segments the measurement process into multiple wavelength channels (at least two different wavelengths in the near infrared range). By measuring at multiple discrete wavelengths rather than a single wavelength, the system can distinguish between water and alcohol absorption signals, thereby improving measurement precision while maintaining relatively simple hardware based on LED sources and detectors
2Device complexity
If measurements are carried out at wavelengths where water absorption dominates, then the measurement setup remains simple, but the method becomes limited to alcohol contents of less than 10% by volume
Solution Approach 1:
The patent extends the measurement from a single wavelength dimension to multiple wavelength dimensions. By selecting at least two different wavelengths in the near infrared range where alcohol and water have different absorption characteristics, the system can determine alcohol content across a broader concentration range (0-100% by volume) while keeping the hardware simple through the use of LED-based light sources
3Device complexity
If a single wavelength measurement method is used, then the device remains simple and cost-effective, but third-party substances in the sample cannot be easily accounted for
Solution Approach 1:
The patent applies segmentation by dividing the spectral measurement into multiple wavelength components. By measuring absorption at at least two different wavelengths, the system can differentiate between the absorption signatures of alcohol, water, and third-party substances, enabling the device to account for interfering substances while maintaining a simple and cost-effective structure based on LED sources and detectors
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 approach provides accurate ethanol concentration measurements across a wide range, achieving better than 0.2 vol.% accuracy, is cost-effective, and allows for easy calibration and use, overcoming the limitations of previous methods by utilizing the linear relationship between alcohol concentration and IR absorption at specific wavelengths.
Implementation Method 1
absorption of IR light by the liquid sample to be examined at a wavelength λ in the range from 1000 nm to 1500 nm
Implementation Method 2
the absorption values obtained for IR light with different wavelengths are evaluated taking into account reference values or constants obtained as part of the calibration measurement(s), in particular by means of a linear approximation method, such as by means of linear regression, multilinear regression or the like
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Method for determining the alcohol content of liquids containing at least water and alcohol, as well as at least one other component of the liquid, namely sugar or the like., wherein the liquid in an analysis cell is irradiated by an IR LED light source emitting infrared radiation with λ = 1000 to 1500 nm, characterized in that - the IR light absorption is measured at at least two different wavelengths and the measured values are converted into information about the alcohol content of the liquid, - wherein the liquid is irradiated with a first IR radiation with a wavelength λ1, where the absorption coefficient of the alcohol A1a and the absorption coefficient of the water A1w are equal, - and with at least a second IR radiation with a wavelength λ2, where the absorption coefficients A2a and A2w are different from each other, and - that the absorption measurements determined by means of an IR detector are supplied to a computing unit for calculating and outputting the alcohol content of the liquid (Fig. 1).