Abstract: An alcohol density sensor for detecting an alcohol density in mixture fuel composed of petroleum-fuel and alcohol is installed in a fuel tank of an automotive vehicle. The alcohol density sensor includes a pair of electrodes immersed in the mixture fuel and a conductor portion for connecting the electrodes to a control unit having a circuit board. The conductor portion is composed of a first conductor portion integrally formed with the electrode and a second conductor portion connected to the first conductor portion. The first conductor portion is led out of a casing containing the electrodes and liquid-tightly sealed at a first through-hole formed in the casing. The second conductor portion is led out of the fuel tank through a second through-hole formed in the fuel tank. Since the first through-hole is sufficiently sealed to prevent pressurized mixture fuel in the casing from leaking into an inner space of the fuel tank, sealing of the second through-hole can be simplified.

Abstract: A position sensor includes a longitudinally extending permanent magnet member at least two longitudinally extending arc-shaped projecting elements respectively projecting from the opposite ends toward the inside space to confront each other at a distance and a pair of compatible main magnetic sensors disposed in the inside space along the longitudinal axis at an interval so as to generate a pair of output signals when the permanent magnet member shifts along the longitudinal axis. The opposite ends of the permanent magnet member are configured to surround a common inside space and polarized to have opposite magnetic poles so as to provide in the inside space a magnetic field whose magnetic flux density becomes a maximum at a longitudinal center of the inside space and gradually becomes smaller as a position of the inside space shifts from the longitudinal center along a longitudinal axis of the permanent magnet members.

Abstract: An alcohol density sensor for detecting an alcohol density in mixture fuel composed of petroleum-fuel and alcohol is installed in a fuel tank of an automotive vehicle. The alcohol density sensor includes a pair of electrodes immersed in the mixture fuel and a conductor portion for connecting the electrodes to a control unit having a circuit board. The conductor portion is composed of a first conductor portion integrally formed with the electrode and a second conductor portion connected to the first conductor portion. The first conductor portion is led out of a casing containing the electrodes and liquid-tightly sealed at a first through-hole formed in the casing. The second conductor portion is led out of the fuel tank through a second through-hole formed in the fuel tank. Since the first through-hole is sufficiently sealed to prevent pressurized mixture fuel in the casing from leaking into an inner space of the fuel tank, sealing of the second through-hole can be simplified.

Abstract: A position sensor includes a longitudinally extending permanent magnet member at least two longitudinally extending arc-shaped projecting elements respectively projecting from the opposite ends toward the inside space to confront each other at a distance and a pair of compatible main magnetic sensors disposed in the inside space along the longitudinal axis at an interval so as to generate a pair of output signals when the permanent magnet member shifts along the longitudinal axis. The opposite ends of the permanent magnet member are configured to surround a common inside space and polarized to have opposite magnetic poles so as to provide in the inside space a magnetic field whose magnetic flux density becomes a maximum at a longitudinal center of the inside space and gradually becomes smaller as a position of the inside space shifts from the longitudinal center along a longitudinal axis of the permanent magnet members.