Patent ID: 6724201
Filing Date: 2004-04-20
Classification: G01F

Abstract:
A resistance-type liquid level measuring apparatus installed in a fuel tank, for detecting a fuel quantity in the tank, comprising a resistance-type sensor including a float floating according to a liquid level, an insulating substrate having a plurality of conductor electrodes connected with a resistor, and a movable contact interlocked with a movement of the float to come in contact with the conductor electrodes on the insulating substrate, whereina material containing silver is used as a material of the conductor electrodes or the movable contact, and a voltage dividing resistance is connected with a power source in series with the resistor, and a voltage of a connection point between the voltage dividing resistance and the resistor is outputted as a signal corresponding to the liquid level, characterized in that resistance values of the voltage dividing resistance and the resistor are set so that a voltage drop VS due to silver sulfide generated between the conductor electrode and the movable contact is less than or equal to 15% with respect to a difference between a voltage VF equivalent to a full tank of the liquid level and a voltage VE equivalent to a low region.