A fluid level sensing system comprises a sensor float assembly, a sensor control module comprising a sensor processor, and a sensor cable. An accelerometer arranged within the float chamber in a fixed orientation relative to a float axis. The accelerometer is capable of determining movement in at least first and second reference axes. The sensor cable is operatively connected between the float processor and the sensor processor. Movement of the float enclosure relative to the reference point is limited. The accelerometer generates and transfers to the float processor first and second sets of data representative of movement along the first and second reference axes. The float processor generates and transfers to the sensor processor pitch data associated with the float enclosure based on the first and second sets of data. The sensor processor generates a status signal and/or a control signal based on the pitch data.

A switching device includes a first enclosure containing a switch, a rod-shaped second enclosure having a second end connected to the first enclosure, a detector unit in the second enclosure, and a float disposed around the second enclosure and capable of moving along it. As the float moves from the first end of the second enclosure toward the second end, when the float enters a first position range, a first position sensor senses the float and transmits a first sensing signal to a detection circuit; when the float enters a second position range, a second position sensor senses the float and transmits a second sensing signal to the detection circuit. The detection circuit close a switch in response to the second sensing signal to turn on an external appliance. The switching device is flexible, reliable, and inexpensive to produce.

A switching device includes a first enclosure containing a switch, a rod-shaped second enclosure having a second end connected to the first enclosure, a detector unit in the second enclosure, and a float disposed around the second enclosure and capable of moving along it. As the float moves from the first end of the second enclosure toward the second end, when the float enters a first position range, a first position sensor senses the float and transmits a first sensing signal to a detection circuit; when the float enters a second position range, a second position sensor senses the float and transmits a second sensing signal to the detection circuit. The detection circuit close a switch in response to the second sensing signal to turn on an external appliance. The switching device is flexible, reliable, and inexpensive to produce.

A tank fill control apparatus comprising: a tank-installed switch, including: a tubular body including an upper end, a lower end, and an annular mounting flange on an outer surface between the upper end and the lower end; a liquid level sensor including a detector, a float in and moveable along a length of the lower end and a rod connecting the float to the detector, the liquid level sensor configured to sense a liquid level relative to the lower end and further configured to generate a signal when at least a maximum selected liquid level is sensed; and a control unit in communication with the tank-installed switch including: a liquid level monitoring function for receiving the signal from the liquid level sensor; and a control function for generating at least one of (i) an alert signal indicating that the maximum selected liquid level is sensed and (ii) a valve control to modify a fill operation from a tank fill system.

A tank fill control apparatus comprising: a tank-installed switch, including: a tubular body including an upper end, a lower end, and an annular mounting flange on an outer surface between the upper end and the lower end; a liquid level sensor including a detector, a float in and moveable along a length of the lower end and a rod connecting the float to the detector, the liquid level sensor configured to sense a liquid level relative to the lower end and further configured to generate a signal when at least a maximum selected liquid level is sensed; and a control unit in communication with the tank-installed switch including: a liquid level monitoring function for receiving the signal from the liquid level sensor; and a control function for generating at least one of (i) an alert signal indicating that the maximum selected liquid level is sensed and (ii) a valve control to modify a fill operation from a tank fill system.

A fluid level monitor incorporated into a fuel tank. A sensor module is adapted to being mounted to an exterior of the tank. A tube extends from the module within the tank and secures a housing at an interior location. The housing has a gear assembly, a float arm pivotally secures to the gear assembly and, in response to changes in a fluid level of the tank, causes the gear assembly to rotate a drive rod extending within the tube. A coupler forms a portion of the sensor module and is secured to an upper end of the drive rod. Rotation of the coupler relative to a PCB integrated into the sensor module produces an inductive signal indicative of the amount of displacement of the float and, consequently, the level of the fluid within the tank.

Tank-installable switches for installation through a thief hatch port on a tank. In some embodiments, the switch may comprise a tubular body and a liquid level sensor. The liquid level sensor may include: a detector; a float in and moveable along a length of the lower end; and a rod connecting the float to the detector. The liquid level sensor may be configured to sense a liquid level relative to the lower end and further configured to generate a signal when at least a maximum selected liquid level is sensed.

Tank-installable switches for installation through a thief hatch port on a tank. In some embodiments, the switch may comprise a tubular body and a liquid level sensor. The liquid level sensor may include: a detector; a float in and moveable along a length of the lower end; and a rod connecting the float to the detector. The liquid level sensor may be configured to sense a liquid level relative to the lower end and further configured to generate a signal when at least a maximum selected liquid level is sensed.

A water-level measuring device using a gear ratio includes: a water pool filled with a liquid; a plot receiving buoyancy by being floated over a water surface of the liquid filled in the water pool; a cable connected to the plot and extending to the outside of the water pool; a first gear connected with the cable; a second gear connected with the first gear; a weight pendulum connected with the second gear and moving in up and down directions, wherein when a water level of the water pool descends, the weight pendulum ascends due to a weight of the plot, and when the water level of the water pool ascends, the weight pendulum descends due to the buoyancy of the plot.

A water-level measuring device using a gear ratio includes: a water pool filled with a liquid; a plot receiving buoyancy by being floated over a water surface of the liquid filled in the water pool; a cable connected to the plot and extending to the outside of the water pool; a first gear connected with the cable; a second gear connected with the first gear; a weight pendulum connected with the second gear and moving in up and down directions, wherein when a water level of the water pool descends, the weight pendulum ascends due to a weight of the plot, and when the water level of the water pool ascends, the weight pendulum descends due to the buoyancy of the plot.