Analysis of ultra-short pulse modulation for NDIR

Chih Hsiung Shen, Shao Tzu Li

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Citation (Scopus)

Abstract

In this research an infrared source which radiation is modulated by supplying the heater of source with an ultrashort alternating voltage are used in gas analyzer operating on the basis of non-dispersive infrared sensing. Beyond the conventional technique of constant periodic heating of infrared light source, we propose a new infrared delta-sigma architecture with closed-loop feedback system is built with the hybrid combination of a CO2 infrared sensor with a specific wavelength filter, an infrared MEMS heater, a chopper amplifier, threshold comparator, ARM based MPU and discrete electronic devices. The thermal properties of light source for ultra-short alternating modulation without the use of a mechanical chopper has been studied from the output signal of infrared sensor within the limit of modulation frequency and energetic efficiency. The numbers of heating and cooling of the heater are count and manipulated to give a ratio which will determine the gas concentration. After a modeling of system, we built a model for the description of relationship between gas concentration and sensor by the duty of heating. The measurement results show a good linear behavior of signal and it proves to be a practical for all the NDIR measuring techniques and this work also gives a new approach not only to measure gas concentration fast but also obtain the high resolution.

Original languageEnglish
Title of host publication2017 International Conference on Circuits, Devices and Systems, ICCDS 2017
PublisherInstitute of Electrical and Electronics Engineers Inc.
Pages184-188
Number of pages5
ISBN (Electronic)9781538618714
DOIs
Publication statusPublished - 2017 Nov 27
Event2017 International Conference on Circuits, Devices and Systems, ICCDS 2017 - Chengdu, China
Duration: 2017 Sep 52017 Sep 8

Publication series

Name2017 International Conference on Circuits, Devices and Systems, ICCDS 2017
Volume2017-January

Other

Other2017 International Conference on Circuits, Devices and Systems, ICCDS 2017
CountryChina
CityChengdu
Period17-09-0517-09-08

    Fingerprint

All Science Journal Classification (ASJC) codes

  • Electrical and Electronic Engineering
  • Instrumentation

Cite this

Shen, C. H., & Li, S. T. (2017). Analysis of ultra-short pulse modulation for NDIR. In 2017 International Conference on Circuits, Devices and Systems, ICCDS 2017 (pp. 184-188). (2017 International Conference on Circuits, Devices and Systems, ICCDS 2017; Vol. 2017-January). Institute of Electrical and Electronics Engineers Inc.. https://doi.org/10.1109/ICCDS.2017.8120475