Title:
ALCOHOL SENSOR FOR INTERNAL COMBUSTION ENGINE
Document Type and Number:
Japanese Patent JPH01138442
Kind Code:
A
Abstract:
PURPOSE:To obtain the inexpensive, high-accuracy sensor by detecting the alcohol content of fuel with which alcohol is mixed optically from the difference in critical angle between gasoline and alcohol. CONSTITUTION:One end of a prism 12 is dipped in the mixed fuel 11 of the gasoline and alcohol and a light beam from a light source 13 is made incident into the fuel 11 from the other end surface 12b of the prism 12. The light is split into total reflected light which is reflected totally by a slanting surface part 12a contacting the fuel 11 and transmitted light, and the ratio of the incidence angles, i.e., critical angles of the both to the fuel 11 differs according to the mixing ratio of the gasoline and alcohol. The outputs of two photodetectors 16 and 17 which photodetect them vary. Here, the difference between the outputs of the photodetectors 16 and 17 are amplified differentially by an operational amplifier 19 to detect the amount of the alcohol contained in the fuel 11 quantitatively.
Inventors:
SHIRAKAWA HIROYUKI
Application Number:
JP29814187A
Publication Date:
May 31, 1989
Filing Date:
November 25, 1987
Export Citation:
Assignee:
MITSUBISHI ELECTRIC CORP
International Classes:
G01N21/41; (IPC1-7): G01N21/41
Attorney, Agent or Firm:
Mamoru Takada (1 person outside)