Methods and apparatus are provided for determining an offset detection for a fuel level sensor fault. The method includes receiving an electrical resistance reading from a potentiometer of a fuel level sensor and generating an estimated fuel level based on an established fuel usage table that references the electrical resistance reading. The fuel level sensitivity is calculated based on the change in electrical resistance readings divided by the change in the estimated fuel levels (R/F). The fuel level sensitivity is compared to a predetermined sensitivity curve to determine any necessary offset to the electrical resistance reading. Finally, the fuel usage table is updated with the offset to the electrical resistance reading.

A device for monitoring a liquid level of a liquid storage tank for a vehicle is capable of improving sensing sensitivity of a liquid level sensor by employing a structure capable of amplifying an electromotive force, which is generated by an electrode, at an electromotive force amplification layer including a carbon micro coil (CMC) and accurately sensing a frozen state of a liquid to perform a heating function so as to resolve the frozen state of the liquid.

A liquid level sensor includes a base member disposed above the liquid. A lever arm is pivotally attached to the base member. The lever arm is configured to interact with the liquid so that it has an angular displacement relative to the base member. The angular displacement is a function of the level of the liquid in the liquid channel. A sensor senses angular displacement of the lever arm. A communications circuit transmits the angular displacement of the lever arm to a remote location. In a method of detecting a liquid level, a float that is buoyant in the liquid is placed into the liquid and is coupled to a lever arm. An angular displacement of the lever arm relative to a base member is measured. The liquid level is a function of the angular displacement of the lever arm.

A liquid level detection device is disposed in a container having a viscous liquid. The liquid level detection device includes an installing seat, a connecting rod, a pivoting structure connecting the installing seat and one end of the connecting rod, and a floating element disposed at one end of the connecting rod opposite to the installing seat. Further, the liquid level detection device includes a protecting bladder disposed to correspond to the pivoting structure. The protecting bladder divides the liquid level detection device into a coated part and an exposed part. One end of the floating element opposite to the installing seat is the exposed part. The protecting bladder isolates the viscous liquid from contacting with the pivoting structure to prevent excessive viscous liquid from remaining on the pivoting structure and avoid the problem of misoperation of the liquid level detection device caused by the influence of the protecting bladder.

An apparatus for determining a vertical level or density profile of a multi-layered fluid column including at least two different liquids, the apparatus comprising: an elongate vertical support member; and a plurality of measurement modules spaced apart, and supported along, the elongate vertical support member to form a vertical array of measurement modules; wherein each measurement module comprises: a support arm mounted to the elongate vertical support member and extending outwardly from the elongate vertical support member; a displacer carried on the support arm; and a force measurement device configured to measure a force attributable to a mass of the displacer mediated by a buoyancy of the displacer in the fluid column, wherein the plurality of measurement modules have a data connection to a data processing unit for transmitting measurement data from the plurality of measurement modules to the data processing unit, and wherein the data processing unit is configured to process the measurement data from the plurality of measurement modules and generate a level or density profile of the fluid column.

Level sensors having conductive target movement sensing are disclosed. An example level sensor includes a lever operatively coupled to a sensing member, a target operatively coupled to the lever, where the target includes a conductor, an inductive coil to generate a magnetic field and measure feedback signatures associated with the target and the magnetic field, and a processor to calculate a position of the sensing member based on the feedback signatures.

A liquid surface detecting device includes a movable body, a circuit board, segment electrodes, an output electrode, and a resistive element located across the segment electrodes and the output electrode to be electrically connected thereto. The segment electrodes are arranged on the mounting surface in an electrode region. The resistive element includes first and second resistive portions on both sides of the electrode region in the movement direction. The resistive element is electrically connected to the output electrode at each of the first and second resistive portions. The movement direction in which the movable body moves according to a decrease of the liquid surface level is defined as a reference direction. The second resistive portion located further in the reference direction than the first resistive portion is completely cut off to block a conduction between its output electrode side and electrode region side.

Level sensors having conductive target movement sensing are disclosed. An example level sensor includes a lever operatively coupled to a sensing member, a target operatively coupled to the lever, where the target includes a conductor, an inductive coil to generate a magnetic field and measure feedback signatures associated with the target and the magnetic field, and a processor to calculate a position of the sensing member based on the feedback signatures.

A device for monitoring a liquid level of a liquid storage tank for a vehicle is capable of improving sensing sensitivity of a liquid level sensor by employing a structure capable of amplifying an electromotive force, which is generated by an electrode, at an electromotive force amplification layer including a carbon micro coil (CMC) and accurately sensing a frozen state of a liquid to perform a heating function so as to resolve the frozen state of the liquid.

In at least some implementations, a fluid level sensor assembly includes a housing, a sensor element carried by the housing, an arm that moves relative to the sensor element, a saddle coupled to at least part of the arm to retain the position of the arm relative to the sensor element, and a retainer. The retainer is coupled to the saddle and overlies a portion of the saddle, the arm or both, to inhibit decoupling of the arm from the saddle.