In situ Measurement of Fuel Concentration of Hydrocarbon near Spark Plug in an Engine Cylinder by 3.392 μm Infrared Laser Absorption Method (Application to Actual Engine)

Eiji Tomita, Nobuyuki Kawahara, Atsushi Nishiyama, Masahiro Shigenaga

Research output: Contribution to journalArticle

1 Citation (Scopus)


An infrared absorption method was used to determine the fuel concentration with a 3.392 μm He-Ne laser. The effects of pressure and temperature on the molar absorption coefficients of hydrocarbon fuels were clarified, so that it increased with increasing temperature and decreased with increasing pressure. Molar absorption coefficient of multi-component fuel like gasoline can be estimated using molar absorption coefficient of each component and considering mass balance. By exchanging an ordinary spark-plug for & spark-plug with a developed sensor in which light can pass through mixture in the combustion chamber, successive measurement of fuel concentration was performed in a spark-ignition engine. The effects of liquid droplets, mechanical vibration, and other gas like H2O on measurement accuracy were discussed.

Original languageEnglish
Pages (from-to)518-524
Number of pages7
JournalNippon Kikai Gakkai Ronbunshu, B Hen/Transactions of the Japan Society of Mechanical Engineers, Part B
Issue number690
Publication statusPublished - Feb 2004



  • Air Fuel Ratio
  • Fiber-Optic Sensor
  • Infrared Absorption Method
  • Internal Combustion Engine
  • Laser Diagnostics
  • Liquid Fuel
  • Molar Absorption Coefficient

ASJC Scopus subject areas

  • Mechanical Engineering

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