Reactive Film CO2 Sensor for Cold Chain Monitoring

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Solution Overview

Problem

Current CO2 sensors used in cold chain applications are expensive and overly precise, making them unsuitable for the cost-effective monitoring of carbon dioxide levels in environments where perishable products are stored or transported, as they require monitoring CO2 concentrations within specific ranges to maintain product freshness and prevent spoilage.

Innovation Solution

A low-cost gas concentration monitoring system utilizing a radiation source, a radiation sensor array, and a reactive material, such as a color-sensitive film, that reacts to CO2 presence by altering the amount of radiation detected, with an analog-to-digital converter to sum and convert signals, allowing for accurate detection of CO2 levels within the necessary range of 1% to 30%.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If non-dispersive infrared technology sensors are used, then measurement precision and device life are improved, but device cost and complexity increase significantly

Engineering Contradiction:
Improvegas concentration detection accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent employs inexpensive optical filters and simple photodetector arrays that can be mass-produced at low cost. The system uses disposable or replaceable filter elements with specific wavelength transmission characteristics, eliminating the need for expensive, complex infrared sensors while achieving sufficient measurement precision for cold chain applications.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention changes the detection parameter from broad-spectrum infrared absorption to wavelength-specific optical absorption using filtered light. By using optical filters to select specific wavelengths and simple photodetectors to measure light intensity, the system achieves adequate CO2 concentration measurement without the complexity of non-dispersive infrared technology.

Inventive Principle:
Principle #35Parameter changes

2Measurement precision

If non-dispersive infrared technology sensors are used, then measurement precision is improved, but device cost increases

Engineering Contradiction:
Improvegas concentration detection accuracyVSAvoidsensor manufacturing cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The patent employs inexpensive optical filters and simple photodetector arrays that can be mass-produced at low cost. The system uses disposable or replaceable filter elements with specific wavelength transmission characteristics, eliminating the need for expensive, complex infrared sensors while achieving sufficient measurement precision for cold chain applications.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

Solution Approach 2:

The invention uses multiple photodetectors with different optical filters to create redundant measurement channels. By copying the basic detection mechanism across multiple wavelength bands, the system achieves robust CO2 concentration measurement through comparative analysis, reducing the need for single high-precision expensive sensors.

Inventive Principle:
Principle #26Copying

3Measurement precision

If sophisticated CO2 sensors are used, then measurement precision is improved, but the precision exceeds the requirements for cold chain applications

Engineering Contradiction:
Improvegas concentration detection accuracyVSAvoidsuitability for cold chain application requirements
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The invention changes the detection parameter from broad-spectrum infrared absorption to wavelength-specific optical absorption using filtered light. By using optical filters to select specific wavelengths and simple photodetectors to measure light intensity, the system achieves adequate CO2 concentration measurement without the complexity of non-dispersive infrared technology.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements multiple photodetector channels with different optical filters, providing more measurement capability than strictly necessary. This partial excess in measurement channels enhances reliability and allows for calibration and compensation, while the overall system remains simpler and more adaptable to cold chain requirements than high-precision infrared sensors.

Inventive Principle:
Principle #16Partial or excessive action

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 system provides a cost-effective and accurate method to monitor CO2 levels, suitable for cold chain applications, enabling non-invasive, real-time monitoring of CO2 concentrations, thereby maintaining product freshness and preventing spoilage, with a simple and affordable sensor that can be used for extended periods before disposal.

Implementation Method 1

a reactive material located between the radiation source and the radiation sensor and configured to react to the presence of a gas, wherein the reaction of the reactive material impacts an amount of radiation at different wavelengths that passes through the reactive material

Methodology Applied
Scientific EffectGas absorption reaction: Absorption (physical)

Implementation Method 2

a radiation sensor comprising a plurality of sensing elements configured to detect radiation received at the radiation sensor from the radiation source

Methodology Applied
Scientific EffectRadiation detection: Photoelectric Effect

Data Source

PatentEP3227666B1Film based carbon dioxide sensor
Publication Date: 2019.02.06 CARRIER CORP
  • EP3227666B1 patent drawingFigure 1
  • EP3227666B1 patent drawingFigure 2

AI summary

A gas concentration monitoring system (100) is provided. The system (100) includes a radiation source (104) having one or more emitting elements and a radiation sensor (106) having one or more sensing elements configured to detect radiation received at the radiation sensor (106). A reactive material (108) is located between the radiation source (104) and the radiation sensor (106) and is configured to react to the presence of a gas such as carbon dioxide, wherein the reaction of the reactive material (108) impacts an amount of radiation detected at the radiation sensor (106).