A sensor includes: an electrostatic-capacity-type sensor electrode layer having a plurality of sensing units; a reference electrode layer opposed to one main face of the sensor electrode layer; and a deformable layer disposed between the reference electrode layer and the sensor electrode layer, the deformable layer being to deform elastically due to application of pressure. The deformable layer is recessed between the sensing units or discontinuous between the sensing units. The reference electrode layer has a shaped portion between the sensing units.

The pressure pad which pressure-sensing fabric which is within a gasket and which measures the distribution of pressure on the gasket. Thus, the gasket protects the pressure-sensing fabric from damage due to water or mechanical trauma. The pressure pad includes multiple piezoresistive depositions of piezoresistive depositions ink or paste which act as individual pressure-sensing points. Conductive tracks between the piezoresistive depositions transmit the pressure measurements in the form of electrical signals. The pressure-sensing fabric is connected to a controller and transmits pressure measurements to the controller. Algorithms stored on the controller create a map of absolute mechanical loading to each pressure-sensing point of the pressure pad. The gasket may be mounted beneath a toilet or between plumbing joints. The pressure pad may detect weaknesses in the gasket, a toilet user's weight, a weight of excrement added to the toilet, or a toilet user's posture.

The present invention concerns a device (101, 102, 103, 104) for measuring force, comprising: a movable member (1); guide means (2) for guiding the movable member along at least one degree of freedom; position measuring means (3) for measuring the position of the movable member; at least one actuator (4) for applying an actuator force (7) to the movable member; a control system (5), arranged to send a control signal to the at least one actuator, the actuator force depending on the control signal, the control system being arranged to modify the control signal according to a measurement of the position of the movable member by the position measuring means; force measuring means (6) arranged to provide, from the control signal sent by the control system to the at least one actuator, a value of a force to be measured (8) being applied to the movable member and separate from the actuator force. The means for guiding the movable member exert no return force on the movable member along the at least one degree of freedom.

A system for performing force sensing with an electromagnetic load may include a signal generator configured to generate a signal for driving an electromagnetic load and a processing subsystem configured to monitor at least one operating parameter of the electromagnetic load and determine a force applied to the electromagnetic load based on a variation of the at least one operating parameter.

Fully-passive sensor systems that receive an input electromagnetic signal and return an output electromagnetic signal are described. The sensor systems can be used to measure pressure in biological or non-biological systems.

A zero-strain soil pressure sensor includes a shell provided with a hydraulic oil cavity and a cavity located below the hydraulic oil cavity, a processor, an outer elastic film arranged at the upper end of the hydraulic oil cavity, an inner elastic film arranged between the hydraulic oil cavity and the cavity, an outer strain bridge circuit connected with the outer elastic film, an inner strain bridge circuit connected with the inner elastic film, a piston communicated with the hydraulic oil cavity, and a driving mechanism connected with the piston. The outer strain bridge circuit, the inner strain bridge circuit and the driving mechanism are electrically connected with the processor. The invention has the beneficial effect that the piston is driven by the driving mechanism to control the oil pressure in the hydraulic oil cavity, external soil pressure is balanced through the oil pressure to keep the outer elastic film in an non-deforming state all the time, and only the inner elastic film is deformed, so that the soil arch effect and soil displacement are avoided, and thus the liquid pressure measured by the inner elastic film is the soil pressure, and the measurement result is more accurate.

A zero-strain soil pressure sensor includes a shell provided with a hydraulic oil cavity and a cavity located below the hydraulic oil cavity, a processor, an outer elastic film arranged at the upper end of the hydraulic oil cavity, an inner elastic film arranged between the hydraulic oil cavity and the cavity, an outer strain bridge circuit connected with the outer elastic film, an inner strain bridge circuit connected with the inner elastic film, a piston communicated with the hydraulic oil cavity, and a driving mechanism connected with the piston. The outer strain bridge circuit, the inner strain bridge circuit and the driving mechanism are electrically connected with the processor. The invention has the beneficial effect that the piston is driven by the driving mechanism to control the oil pressure in the hydraulic oil cavity, external soil pressure is balanced through the oil pressure to keep the outer elastic film in an non-deforming state all the time, and only the inner elastic film is deformed, so that the soil arch effect and soil displacement are avoided, and thus the liquid pressure measured by the inner elastic film is the soil pressure, and the measurement result is more accurate.

Embodiments of the invention relate to a thrust stand and a method of measuring thrust. Embodiments of the invention pertain to a method of calibrating a thrust stand. Embodiments of the subject thrust stand can incorporate a passive eddy current based damper. Specific embodiments of the passive eddy current based damper can function without contact with the balance arm. Further specific embodiments of the passive eddy current based damper can be used in a vacuum. Embodiments can utilize signal analysis techniques to identify and reduce noise. A logarithmic decrement method can be used to calibrate the thrust stand. Force measurements can be made with embodiments of the subject thrust stand for a standard macroscale dielectric barrier discharge (DBD) plasma actuator and/or other thrust producing devices.

A zero-strain soil pressure sensor includes a shell provided with a hydraulic oil cavity and a cavity located below the hydraulic oil cavity, a processor, an outer elastic film arranged at the upper end of the hydraulic oil cavity, an inner elastic film arranged between the hydraulic oil cavity and the cavity, an outer strain bridge circuit connected with the outer elastic film, an inner strain bridge circuit connected with the inner elastic film, a piston communicated with the hydraulic oil cavity, and a driving mechanism connected with the piston. The outer strain bridge circuit, the inner strain bridge circuit and the driving mechanism are electrically connected with the processor. The invention has the beneficial effect that the piston is driven by the driving mechanism to control the oil pressure in the hydraulic oil cavity, external soil pressure is balanced through the oil pressure to keep the outer elastic film in an non-deforming state all the time, and only the inner elastic film is deformed, so that the soil arch effect and soil displacement are avoided, and thus the liquid pressure measured by the inner elastic film is the soil pressure, and the measurement result is more accurate.

A zero-strain soil pressure sensor includes a shell provided with a hydraulic oil cavity and a cavity located below the hydraulic oil cavity, a processor, an outer elastic film arranged at the upper end of the hydraulic oil cavity, an inner elastic film arranged between the hydraulic oil cavity and the cavity, an outer strain bridge circuit connected with the outer elastic film, an inner strain bridge circuit connected with the inner elastic film, a piston communicated with the hydraulic oil cavity, and a driving mechanism connected with the piston. The outer strain bridge circuit, the inner strain bridge circuit and the driving mechanism are electrically connected with the processor. The invention has the beneficial effect that the piston is driven by the driving mechanism to control the oil pressure in the hydraulic oil cavity, external soil pressure is balanced through the oil pressure to keep the outer elastic film in an non-deforming state all the time, and only the inner elastic film is deformed, so that the soil arch effect and soil displacement are avoided, and thus the liquid pressure measured by the inner elastic film is the soil pressure, and the measurement result is more accurate.