A system for preventing overflow of a toilet includes a sensor, a processor and an actuator. The sensor senses a parameter caused by fluid dynamics within the toilet during a flush cycle. The parameter may involve vibration, sound, pressure, fluid flow rate or other detectible characteristics of the toilet. The processor uses information regarding the parameter that is gathered by the sensor to evaluate the condition of the flush cycle to determine if an impeded flush condition exists. In the event of an impeded flush condition, the processor directs the actuator to close a valve, which may be the toilet flapper valve in some embodiments. Also disclosed are methods for preventing toilet overflow, detecting an impeded flush condition and calibrating the system.

A solid state fuel level sensor system disposed in a fuel tank according to one example of the present disclosure includes a first pressure sensor, a second pressure sensor, a reference chamber, a liquid discriminating membrane and a reference tube. The first pressure sensor is disposed in the fuel tank. The second pressure sensor is disposed in the fuel tank. The first and second pressure sensors are separated a vertical distance from each other in the fuel tank. The reference chamber is fluidly connected to the first and second pressure sensors. The reference tube is fluidly connected between the reference chamber and the liquid discriminating membrane. The reference tube extends into a vapor space of the fuel tank at the liquid discriminating membrane such that a vapor pressure at the vapor space is communicated into the reference chamber.

A micrometer system and water holding cup and related for use in connection with a hydrostatic level-measuring system for measuring with precision, a level normal to gravitation of physical surfaces, the micrometer system comprising: a micrometer; an elongated micrometer probe tip at a lower extremity of the micrometer; a micrometer dial for extending and retracting the probe tip in response to a dialing thereof; a micrometer alignment section fixed to the micrometer, and a substantially rigid support structure for supporting the a micrometer alignment section at a fixed height above the physical surfaces when a footing of the support structure is rested upon the physical surfaces. The cup comprises mirroring on a bottom surface thereof; at least one reference feature on the mirroring surface for providing to a user, a visual reference for at least one micrometer grade marker reflected by the mirroring surface, for dialing a micrometer.

A method of measuring a height of a fuel in an aircraft fuel tank (21) b including illuminating the fuel in the aircraft fuel tank and detecting reflected light from the fuel. Optical coherence tomography is used to determine the height of a surface of fuel in the fuel tank. An apparatus (30) is used to measure a height of a surface of fuel in an aircraft fuel tank, and an aircraft fuel tank system with a fuel tank and an apparatus for measuring a height of a surface of fuel in the aircraft fuel tank.

Methods, apparatuses, and storage mediums are provided for detecting water shortage for a humidifier. The method includes: obtaining a water level parameter of a water tank; determining a water level state of the water tank according to the water level parameter. When the water level state of the water tank is a water shortage state, energizing a valve connected to a water box so that water can be added to the water tank through the valve. A number of times of energizing the valve is recorded. When the number of times of energizing the valve exceeds a first preset number of times as well as when the water level state of the water tank determined every time after energization of the valve is the water shortage state, confirming that the water box is short of water.

An aircraft fuel system comprises an integrated sensor assembly incorporating a housing. The housing receives a circuit board, a temperature sensor, a point level sensor and a fuel density sensor. A first fuel height sensor is positioned outwardly of the housing.

A system for preventing overflow of a toilet includes a sensor, a processor and an actuator. The sensor senses a parameter caused by fluid dynamics within the toilet during a flush cycle. The parameter may involve vibration, sound, pressure, fluid flow rate or other detectible characteristics of the toilet. The processor uses information regarding the parameter that is gathered by the sensor to evaluate the condition of the flush cycle to determine if an impeded flush condition exists. In the event of an impeded flush condition, the processor directs the actuator to close a valve, which may be the toilet flapper valve in some embodiments. Also disclosed are methods for preventing toilet overflow, detecting an impeded flush condition and calibrating the system.

A system for preventing overflow of a toilet includes a sensor, a processor and an actuator. The sensor senses a parameter caused by fluid dynamics within the toilet during a flush cycle. The parameter may involve vibration, sound, pressure, fluid flow rate or other detectible characteristics of the toilet. The processor uses information regarding the parameter that is gathered by the sensor to evaluate the condition of the flush cycle to determine if an impeded flush condition exists. In the event of an impeded flush condition, the processor directs the actuator to close a valve, which may be the toilet flapper valve in some embodiments. Also disclosed are methods for preventing toilet overflow, detecting an impeded flush condition and calibrating the system.

A system for preventing overflow of a toilet includes a sensor, a processor and an actuator. The sensor senses a parameter caused by fluid dynamics within the toilet during a flush cycle. The parameter may involve vibration, sound, pressure, fluid flow rate or other detectible characteristics of the toilet. The processor uses information regarding the parameter that is gathered by the sensor to evaluate the condition of the flush cycle to determine if an impeded flush condition exists. In the event of an impeded flush condition, the processor directs the actuator to close a valve, which may be the toilet flapper valve in some embodiments. Also disclosed are methods for preventing toilet overflow, detecting an impeded flush condition and calibrating the system.

A liquid level sensor 1 comprises a sleeve 2 disposed so as to extend in the vertical direction, a float 3 configured so as to move along said sleeve according to fluctuation of liquid level, a resistor string 4, a plurality of grounding means 5 disposed inside the sleeve 2 and a liquid level signal output means 6 to take out an electric signal detected between a positive electrode side end part 4a and a junction part grounded by the grounding means 5 as a liquid level signal that is a signal corresponding to the liquid level, and further comprises a warning signal output means 7 to output a warning signal when the float 3 is located within a predetermined distance from a warning position that is a predetermined position within a movable range of the float 3. Thereby, a compact and reliable liquid level sensor is realized.