An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).

A vibration rectification error correction circuit includes a first correction circuit that obtains a digital value based on a signal to be measured output from a sensor element configured to measure a physical quantity and corrects a vibration rectification error of the digital value by a correction function based on a product of values obtained by biasing the digital value.

A vibration rectification error correction circuit includes a first correction circuit that obtains a digital value based on a signal to be measured output from a sensor element configured to measure a physical quantity and corrects a vibration rectification error of the digital value by a correction function based on a product of values obtained by biasing the digital value.

A single axis accelerometer comprising a swing arm pivotally attached to a frame is held in apposition to a stop by a threshold force until an experienced acceleration force greater than the threshold force causes a distal segment of the swing arm to release from the stop and move toward a sensor that is activated by a sensor trigger on the distal segment of the swing arm.

An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).

A cantilever section as a substrate for a sensor includes: a base section; a movable section connected to the base section; an arm portion as a support portion extending along the movable section from the base section when viewed in a planar view as viewed from a thickness direction of the movable section; and a gap portion formed to have a predetermined gap between the movable section and the arm portion when viewed in the planar view, in which a ridge portion formed as an etching residue having a top portion on the side facing the gap portion is provided on each of facing surfaces of the movable section and the arm portion in the gap portion, and the predetermined gap is a gap between a top portion of a first ridge portion which is the ridge portion formed at one of the movable section and the arm portion, and a top portion of a second ridge portion which is the ridge portion formed at the other of the movable section and the arm portion.

A cantilever section as a substrate for a sensor includes: a base section; a movable section connected to the base section; an arm portion as a support portion extending along the movable section from the base section when viewed in a planar view as viewed from a thickness direction of the movable section; and a gap portion formed to have a predetermined gap between the movable section and the arm portion when viewed in the planar view, in which a ridge portion formed as an etching residue having a top portion on the side facing the gap portion is provided on each of facing surfaces of the movable section and the arm portion in the gap portion, and the predetermined gap is a gap between a top portion of a first ridge portion which is the ridge portion formed at one of the movable section and the arm portion, and a top portion of a second ridge portion which is the ridge portion formed at the other of the movable section and the arm portion.

A vibration rectification error correction circuit includes a first correction circuit that obtains a digital value based on a signal to be measured output from a sensor element configured to measure a physical quantity and corrects a vibration rectification error of the digital value by a correction function based on a product of values obtained by biasing the digital value.

An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).

An environmental condition may be measured with a sensor (10) including a wire (20) having an ultrasonic signal transmission characteristic that varies in response to the environmental condition by sensing ultrasonic energy propagated through the wire using multiple types of propagation, and separating an effect of temperature on the wire from an effect of strain on the wire using the sensed ultrasonic energy propagated through the wire using the multiple types of propagation. A positive feedback loop may be used to excite the wire such that strain in the wire is based upon a sensed resonant frequency, while a square wave with a controlled duty cycle may be used to excite the wire at multiple excitation frequencies. A phase matched cone (200, 210) may be used to couple ultrasonic energy between a waveguide wire (202, 212) and a transducer (204, 214).