A capacitive liquid level sensor (1). The sensor comprises a sensor body in the form a tongue with a freely depending portion (3) extending to a distal tip (6) at its lowermost end. A set of spaced capacitive electrodes (7) extend along the tongue towards the distal tip. In use, when the distal tip (6) of the tongue is immersed in a body of liquid, the capacitance between the electrodes (7) changes depending on the depth of the body of liquid. The width of the tongue increases in the downward direction at least for part of the bottom half of the freely depending part of the tongue.

A sensor includes a planar T-resonator and an oscillator. The planar T-resonator can be a branched T-resonator with at least two symmetrical branches coupled to a stub. The oscillator has an input coupled to the planar T-resonator and an output. The oscillator has a negative resistance within a predetermined frequency range. The oscillator can be configured so that it has an input phase approximately equal to a phase of the planar T-resonator over a majority of the predetermined frequency range.

A capacitive level sensor device, for detecting the level of a medium contained in a container, comprises a circuit support, which extends longitudinally substantially according to level-detection axis. The circuit support has, in a detection region thereof, at least one first plurality of first capacitive elements, which comprise at least one first array of first electrodes, preferably spaced from one another along the level-detection axis, which are arranged in a position corresponding to at least one first side of a supporting structure of the circuit support. The sensor device has a casing body which comprises an electrically insulating and fluid-tight detection portion, which covers the detection region of the circuit support. The detection portion of the casing body comprises an overmoulded outer coating, made of a first electrically insulating polymeric material, which defines an outer surface of the casing body designed to be in contact with the medium the level of which has to be detected. Between the overmoulded outer coating and the first electrodes there is set at least one intermediate layer made of an electrically insulating material different from the first material. The at least one intermediate layer comprises a layer made of a material selected from among materials that include silicon, or derivatives or compounds thereof, and materials that include fluorine derivatives or compounds.

A sensor system for counting elements of a flow of harvested material is disclosed. The sensor system comprises an oscillating circuit and a measuring device, wherein the oscillating circuit comprises at least one capacitive component with a capacitance and an inductive component with an inductance. The oscillating circuit has a resonance frequency which depends on the capacitance and the inductance. Further, the capacitive component is positioned in the region of the flow of harvested material, so that the capacitance is influenced by individual elements of the flow of harvested material. The measuring device is configured to determine the resonance frequency of the oscillating circuit. In this way, the sensor system is configured to deduce at least one property of the particular element of the flow of harvested material from the resonance frequency of the oscillating circuit.

The present invention comprises a novel foldable and intrinsically safe planar coiled inductance sensor to measure liquid depths, solids in liquid depths, and two different liquids depths. This invention is used in onsite wastewater management systems (OWTS) to monitor depths of solids, oil, and effluent in a wastewater tank. The inductors are configured to allow for solids, liquids and gases to surround the coils. A number of coils are hung in series from near the OWTS tank lid to at least 18 inches below the output baffle to measure the different materials at different depths in the OWTS tank. The inductance sensors are capable of use with various materials to measure solids, oil, and effluent depths in an OWTS tank.

A horizontal automatic submersible pump includes a capacitive liquid level sensor, a circuit board and a motor. The capacitive liquid level sensor is arranged inside a casing of the horizontal automatic submersible pump. The capacitive liquid level sensor is configured to detect a liquid level outside the casing of the horizontal automatic submersible pump. The output terminal of the capacitive liquid level sensor is connected to the input terminal of the circuit board. The control terminal of the motor is connected to the output terminal of the circuit board. The circuit board is configured to control the motor to work or stop according to a detection signal of the capacitive liquid level sensor. The horizontal automatic submersible pump starts and stops automatically, and the capacitive liquid level sensor means there are fewer moving parts, which makes the pump less expensive to manufacture, more dependable and longer lasting.

A fluid dispenser, such as a skincare product dispenser, comprises a dispenser housing configured to hold a reservoir of fluid for dispensing and a drive assembly for interacting with the reservoir and causing dispensing of the fluid. A fluid detection sensor is positioned within the dispenser housing proximate the reservoir and configured to detect a capacitance level therein. A controller is configured to determine, based on data from the fluid detection sensor, a change in the fluid level across a dispense. The controller is also configured to determine, based on the determined change, that the fluid level in the reservoir reaches a threshold level and cause an action, such as providing an alert, sending information to a remote server, or modifying an operating parameter.

Devices, systems and methods for process monitoring are presented. For instance, the device includes a crystal and a reactance sensor. The crystal is connected to a frequency measurement circuit. The reactance sensor is connected to the crystal. The reactance sensor is configured to detect a change in a process parameter. The frequency measurement circuit detects the change in the process parameter as a change in the frequency of the crystal. In another example, the system includes a reactance sensor and a measurement device. The reactance sensor is disposed in a process chamber, and has a variable reactance responsive to a change in a process parameter. The measurement device is disposed outside the process chamber and has a frequency measurement circuit. The frequency measurement circuit includes a crystal and is connected to the reactance sensor, and detects the change in the process parameter as a change in the frequency of the crystal.

A capacitive level sensor comprises a control circuit, a supporting structure and a detection structure on the supporting structure. The detection structure comprises a plurality of electrodes, each including a connection part and a plurality of detection parts which extend in a transverse direction relative to a length direction of the sensor, the detection parts of a first electrode being interdigitated with respect to the detection parts of a second electrode. The detection structure includes a plurality of detection sections, which extend in succession in the length direction and include an upper section and one or more underlying lower sections. Each detection section includes respective first and second electrodes, which are electrically insulated from one another and with respect to the first and second electrodes of the other detection sections. The control circuit is prearranged for selectively applying an electrical potential difference between the first and second electrodes of a corresponding detection section, for detecting a value of electrical capacitance therebetween, and deriving therefrom the level of a medium.

The present invention is directed to a capacitive sensor that has electrodes externally positioned on or proximate to the surface of a non-metallic container for detecting a usage level inside the container, where the contents may be liquid or granular solids. By generating an excitation signal to the electrodes and processing the resulting signal waveform, the usage level may be detected with respect to the position of the electrodes. Consequently, embodiments provide a marker that is indicative of usage conditions such as a refill condition or an empty condition in order to inform the user to purchase a refill of the contents. Embodiments may operate with an Internet of Things device so that physical goods may be automatically ordered when the contents are at or below a predetermined level. Embodiments may provide a low cost design and may be used in many applications, such as an oil diffuser.