Non-Modulated Infrared Sensor for Quantitative Halogen Leak Detection
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Solution Overview
Problem
Existing handheld gas leak detectors using heating diode and negative corona discharge technologies suffer from issues such as short life, false alarms, poor stability, low accuracy, and inability to quantitatively detect gas leakage, while modulated infrared sensors face challenges with low signal-to-noise ratio, energy consumption, and missed leak points due to chopping.
Innovation Solution
A non-modulated infrared sensor with a simple structure comprising an infrared transmitter, optical filter, absorption cell, and receiver, connected to a single-chip microcomputer system, uses a solenoid valve for gas switching and employs a quantitative detection method involving continuous light emission, data collection, and signal processing through Fourier and median sliding filtering algorithms to accurately detect gas leakage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Difficulty of detecting and measuring
If modulated light source is used in infrared sensor, then detection capability is improved, but signal-to-noise ratio deteriorates and response speed decreases
Solution Approach 1:
The patent inverts the conventional modulated infrared detection approach by using a continuous infrared light source instead of a modulated one. This inversion allows the system to detect halogen gas leaks through direct absorption measurement without the signal chopping that causes low signal-to-noise ratios, thereby improving both detection capability and measurement precision simultaneously
Solution Approach 2:
The patent changes the operational parameter of the infrared light source from modulated (intermittent) to continuous emission. This parameter change eliminates the periodic blanking effect of modulation, maintaining constant illumination through the gas sample and enabling continuous measurement with higher signal-to-noise ratio and faster response speed
2Difficulty of detecting and measuring
If chopper is used in infrared sensor, then light modulation is achieved, but energy consumption increases and reliability decreases
Solution Approach 1:
The patent extracts and removes the chopper component from the infrared detection system. By eliminating the mechanical chopper that causes reliability issues and high energy consumption, the system achieves light modulation through alternative means (continuous source with electronic detection), thereby improving reliability while maintaining detection capability
Solution Approach 2:
The patent replaces the mechanical chopper system with an electronic detection approach using a continuous infrared source. This substitution eliminates moving parts and mechanical wear, reducing energy consumption and improving reliability while achieving the necessary light modulation through electronic signal processing rather than mechanical chopping
3Difficulty of detecting and measuring
If chopper is used in infrared sensor, then light modulation is achieved, but detection blind spots are created and leak points may be missed
Solution Approach 1:
The patent implements continuous infrared light emission through the gas sample without periodic interruption. This continuity of useful action ensures that the detection beam is always present, eliminating detection blind spots and preventing missed leak points, while achieving modulation through electronic detection methods rather than mechanical chopping
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 quickly locates leak points without blind areas, provides accurate gas leakage quantification, and enhances detection reliability by eliminating interference from background gases, ensuring real-time and precise gas concentration measurement.
Implementation Method 1
the infrared transmitter is a single-channel detector; an infrared light source of the infrared receiver passes through a constant voltage power supply circuit
Implementation Method 2
comprising an infrared transmitter, an optical filter, an infrared, absorption cell and an infrared receiver, the infrared transmitter and the optical filter being sequentially installed at one end of the infrared absorption cell
Data Source
AI summary
A non-modulated infrared sensor for a handheld halogen leak detector and a quantitative detection method thereof, the sensor comprising an infrared transmitter, an optical filter, an infrared absorption cell and an infrared receiver, the infrared transmitter and the optical filter being sequentially installed at one end of the infrared absorption cell, and the infrared receiver being installed at the other end of the infrared absorption cell; the infrared absorption cell is composed of a light source chamber, a gas chamber channel and an infrared-receiver chamber that are sealingly connected in sequence, the light source chamber and the infrared-receiver chamber are respectively provided with a gas inlet and a gas outlet, and the gas inlet is communicated with the target gas or the background gas through a solenoid valve; an infrared light source of the single-channel infrared receiver passes through a constant voltage power supply circuit; and the infrared receiver is connected to a single-chip microcomputer control system through an amplification filter module and an analog-digital conversion module, and the single-chip microcomputer control system is in control connection with the solenoid valve. The present invention has a simple structure and can not only locate the leak point quickly, has no blind area and will not miss leak point, but can also detect the amount of gas leakage with more accurate detection results.