# Lightweight, Compact, and High-Sensitivity Passive Fourier Transform Infrared Spectroscopy-Based Gas Detection System

## TL;DR

This paper introduces a compact gas detection system using infrared spectroscopy that is highly sensitive and suitable for real-world applications.

## Contribution

The system integrates an improved interferometer and novel oversampling method to enhance stability and accuracy.

## Key findings

- The system detects sulfur hexafluoride (SF6) with a detection limit of less than 20 ppm.
- Flight tests confirmed the system's effectiveness in real-world scenarios.
- The system shows high sensitivity, flexibility, and real-time performance.

## Abstract

With the intensification of environmental pollution and the increasingly prominent problem of industrial harmful gas emissions, existing mainstream gas detection technologies still have obvious limitations in terms of real-time performance, non-contact capability, detection accuracy, and multi-component identification. To address this demand, this paper proposes a lightweight and compact gas detection system based on passive Fourier Transform Infrared Spectroscopy (FTIR). The system innovatively integrates an improved parallel pendulum mirror interferometer and a low-noise signal preprocessing module, and simultaneously presents a novel oversampling method fusing equal time, equal optical path difference, and digital filtering, which effectively enhances the operational stability and sampling accuracy of the spectrometer. The system features excellent platform adaptability and can be flexibly mounted on various operation carriers. Combined with a two-dimensional rotating platform and an inertial navigation module, its monitoring range and application scenarios can be further expanded. Indoor sensitivity test results show that the detection limit of the system for sulfur hexafluoride (SF6) is less than 20 ppm; flight tests under real-world scenarios have successfully achieved accurate detection of SF6 gas, fully verifying the practical application effectiveness of the system. Based on the comprehensive results of indoor and outdoor tests, the system demonstrates core technical advantages of high sensitivity, strong flexibility, and excellent real-time performance. It is expected to be widely applied in gas monitoring tasks across multiple fields such as industrial safety monitoring, ecological environment monitoring, and transportation support in the future.