A pressure sensing method includes providing a first receive antenna array that receives a first signal at a first frequency, providing a second receive antenna array that receives a second signal at a second frequency that differs from the first frequency, coupling a diode to the first receive antenna array and the second receive antenna array, coupling a transmit antenna array to the diode, receiving, by the diode, the first signal at the first frequency and the second signal at the second frequency, outputting, by the diode, a third signal at a third frequency that is a difference between the first frequency and the second frequency, receiving, by the transmit antenna array from the diode, the third signal at the third frequency, and outputting, by the transmit antenna array, the third signal at the third frequency.

A pressure sensing method includes providing a first receive antenna array that receives a first signal at a first frequency, providing a second receive antenna array that receives a second signal at a second frequency that differs from the first frequency, coupling a diode to the first receive antenna array and the second receive antenna array, coupling a transmit antenna array to the diode, receiving, by the diode, the first signal at the first frequency and the second signal at the second frequency, outputting, by the diode, a third signal at a third frequency that is a difference between the first frequency and the second frequency, receiving, by the transmit antenna array from the diode, the third signal at the third frequency, and outputting, by the transmit antenna array, the third signal at the third frequency.

A separation system and method, of which the system includes a separation device comprising a mixed fluid inlet, a first outlet, and a second outlet, a tank coupled to the second outlet and configured to receive a solid from the separation device via the second outlet, and a solids-level sensor extending through the tank and positioned at an elevation above a bottom of the tank. The solids-level sensor is configured to detect a viscosity of a material within the tank at the elevation.

A separation system and method, of which the system includes a separation device comprising a mixed fluid inlet, a first outlet, and a second outlet, a tank coupled to the second outlet and configured to receive a solid from the separation device via the second outlet, and a solids-level sensor extending through the tank and positioned at an elevation above a bottom of the tank. The solids-level sensor is configured to detect a viscosity of a material within the tank at the elevation.

A system analyzes a state of an inductive operator. The system includes a measuring device that is configured to: detect an acoustic reference signal and a plurality of operating variables, which can change over time, of the inductive operator or a reference inductive operator during a reference time period; and detect an acoustic signal and the operating variables during a productive time period. The system also includes an evaluating device that is configured to: generate a reference data set from the reference signal and a productive data set from the acoustic signal; perform a regression analysis of the reference data set and thereby create a model for description of the acoustic reference signal by the operating variables; and generate a state evaluation of the inductive operator from a difference between the productive data set and values modelled in accordance with the model.

A wave-source-direction estimation device includes: a plurality of input units that acquires, as input signals, electrical signals based on waves detected by a plurality of sensors; a signal selection unit that selects a plurality of pairs that are each a combination of two input signals from among a plurality of the input signals; a relative delay time calculation unit that calculates, as relative delay times, arrival time differences of the waves at the sensors that are supply sources of the two input signals composing each of the pairs, for each wave source direction; and an integrated-estimated-direction-information calculation unit that generates per-frequency estimated direction information for each of the pairs using the input signals composing each of the pairs and the relative delay times of each of the pairs and generates integrated estimated direction information by assigning a weight to and integrating the estimated direction information on all the pairs.

A wave-source-direction estimation device includes: input units that acquire, as input signals, electrical signals that have been converted from waves acquired by sensors; a signal selection unit that selects at least two pairs that are each a combination of at least two input signals from among the input signals; a relative delay time calculation unit that calculates, as relative delay times, arrival time differences of the waves for each wave source searching direction between the at least two input signals composing one of the pairs of the input signals; at least one per-frequency estimated-direction-information generation unit that uses the pairs of the input signals and the relative delay times to generate estimated direction information on a wave source of the waves for each frequency; and an integration unit that integrates the estimated direction information generated for each frequency by the per-frequency estimated-direction-information generation unit.

A measurement terminal includes: a storage that stores, for each of one or more inspection objects, setting information including a parameter related to a feature of an inspection and an abnormality; a processor; and a memory having instructions that, when executed by the processor, cause the processor to perform operations. The operations include: acquiring audio data of sound from an inspection object; deriving, based on the setting information of a corresponding one of the one or more inspection objects, a required time for acquiring the audio data of sound from the inspection object to be used for determining a presence or absence of the abnormality in the inspection object; and determining the presence or absence of the abnormality in the inspection object based on the audio data of sound from the inspection object for the derived required time.

A method determines the travel of a clutch in a hydraulic clutch-actuation system. A hydraulic signal which extends between a transmitting end and a receiving end is acted upon by an acoustic signal for the generation of a wave packet. The acoustic signal on the transmitting end of the clutch-actuation system is fed into the hydraulic fluid, a wave packet generated by the acoustic signal on the receiving end is reflected back to the transmitting end, a running time of the transmitted and reflected wave packet on the transmitting end is evaluated to determine the coupling travel.

An acoustic sensor has a MEMS die with MEMS structure. Among other things, the MEMS structure includes a diaphragm configured to mechanically respond to incident acoustic signals, and a temperature sensor member configured to detect temperature.