SENSOR FOR MIXING RATIO OF GASOLINE AND ALCOHOL OR THE LIKE

摘要

A sensor for mixing ratio of liquid fuel comprising: a cylindrical enclosure having both inlet and outlet opening to act as a passage through which a mixing liquid fuel flows; a transparent column concentrically disposed into the enclosure to make outer surface contact with the liquid fuel: light emitting diode and photo diode each provided so as to sandwich the column in the lengthwise direction, so that the light emitted from the former enters the column through its one end and reflects at the boundary of the column and the liquid fuel, and go out of the other end thereof to fall on the latter; a temperature compensation photo diode disposed in the enclosure with the light of the light emitting diode partly as a light source to rectify the characteristics influenced under the ambient temperature variation; a voltage control circuit provided to control the voltage across the light emitting diode so as to maintain uniform output from the temperature compensation photo diode.