Miniaturised Infrared Spectrophotometer for Low Power Consumption Multi-Gas Sensing

Abstract

<jats:p>Concept, design and practical implementation of a miniaturized spectrophotometer, utilized as a mid-infrared-based multi gas sensor is described. The sensor covers an infrared absorption wavelength range of 2.9 to 4.8 um, providing detection capabilities for carbon dioxide, carbon monoxide, nitrous oxide, sulphur dioxide, ammonia and methane. A lead selenide photo-detector array and customized MEMS-based micro-hotplate are used as the detector and broadband infrared source, respectively. The spectrophotometer optics are based on an injection moulded Schwarzschild configuration incorporating optical pass band filters for the spectral discrimination. This work explores the effects of using both fixed-line pass band and linear variable optical filters. We report the effectiveness of this low-power-consumption miniaturized spectrophotometer as a stand-alone single and multi-gas sensor, usage of a distinct reference channel during gas measurements, development of ideal optical filters and spectral control of the source and detector. Results also demonstrate the use of short-time pulsed inputs as an effective and efficient way of operating the sensor in a low-power-consumption mode. We describe performance of the spectrometer as a multi-gas sensor, optimizing individual component performances, power consumption, temperature sensitivity and gas properties using modelling and customized experimental procedures.</jats:p>

Review of Miniaturized Computational Spectrometers

“…Also, Erfan et al [204] developed a MEMS-based MCS specifically for gas sensing in the 1300-1500 nm wavelength range, capable of detecting acetylene (C 2 H 2 ), water vapor (H 2 O), and CO 2 . Muhiyudin et al [205] developed MCS multi-gas sensing device with low power consumption. The sensor can be used to sense CO 2 , carbon monoxide, nitrous oxide, sulphur dioxide, ammonia, and methane.…”

Review on Hollow-Core Fiber Based Multi-Gas Sensing Using Raman Spectroscopy

“…In the realm of fiber optic gas sensing technology, techniques such as the laser absorption spectrometer (LAS), photothermal spectroscopy (PTS), photoacoustic spectroscopy (PAS), and methods based on the Raman spectroscopy occupy the field. With its origins in 1979, the infrared absorption spectroscopy is now widely used for gas identification [10][11][12][13][14]. Gases with different structures have distinct energy levels, leading to the absorption of photons at specific frequencies.…”

Micro-Electro-Mechanical Systems in Light Stabilization

“…However, the progress of miniaturization has not stopped at the mini-spectrometer level, because optical sensors using micro-electro-mechanical systems (MEMS) technology have been developed. In the meantime, a number of scientific publications have been produced on research in various areas of these sensors’ applications [ 12 , 13 , 14 , 15 , 16 , 17 , 18 , 19 , 20 ]. Unfortunately, there have also been critical opinions about the MEMS technology applications in spectral analysis.…”