An ultrasonic flow sensor is configured to determine the time-of-flight of ultrasonic waves and calculate a change in the speed of sound on the basis of the time-of-flight, to calculate the expected change in speed of sound as a function of the detected temperature of the fluid, to determine if the expected change in speed of sound corresponds to the change in the speed of sound calculated on the basis of the time-of-flight; and to identify a no-flow state, in which there is no flow of the fluid when the expected change in the speed of sound corresponds to the change in the speed of sound calculated on the basis of the time-of-flight, and a temperature difference between the surroundings and the fluid is below a predefined level which is pre-set at a fixed level between 0.01 degree Celsius and 0.5 degree Celsius.

A flow sensor configured to measure the flow of a fluid flowing through a tubular structure comprises a first detection unit that is configured to detect flows above a predefined lower flow level representing the lowest flow that can be measured by the first detection unit and a second detection unit that is configured to estimate the flow below the lower flow level (on the basis of the temperature difference between the surroundings and a fluid). The second detection unit is configured to estimate the flow below the lower flow level on the basis of one or more measurements made in a flow-calibration-area in which the flow sensor can detect the flow and in which the flow depends on the temperature difference.

A sensor assembly is provided for conductivity measurement and ultrasonic temperature measurement. The assembly includes an elongated sensor body aligned along a longitudinal axis extending from an electronics housing. The sensor body has a plurality of elongated electrodes disposed about the longitudinal axis defining a measurement section, and a pair of ultrasonic transceivers mounted to the body in spaced relationship across the measurement section, in which a first transceiver of the pair is attached to a proximal end of the sensor body and a second transceiver of the pair is attached to a distal end of the sensor body across the measurement section. The electronics housing is in operable communication with the plurality of electrodes and to the pair of ultrasonic transceivers to measure fluid parameters within the measurement section.

A method and a measuring apparatus for determining specific quantities for the gas quality in which the gas or gas mixture flows through an ultrasonic flow sensor as well as through a microthermal sensor, and the former is used for determining the sound and flow velocity and the latter for determining the thermal conductivity and the thermal capacity of the gas or gas mixture. The sound velocity, the thermal conductivity and the thermal capacity are subsequently used for the correlation of the specific quantities for the gas quality.

Provided are a flowmeter that can measure a flow rate of a liquid with high accuracy and that is easy to carry and handle, and a dialysis machine and a medicinal solution injection device that employ the flowmeter. A flowmeter includes a tube connection member and a measurement instrument body. The tube connection member includes a tube-shaped body, a plurality of resonators that are arranged with gaps there between on an inner wall surface of the body, resonator-side antennas that are connected to the plurality of resonators and a heating element that is arranged between the pluralities of resonators. The measurement instrument body includes measurement-instrument-side antennas, temperature measurement units that are connected to the measurement-instrument-side antennas and measure a temperature, and a flow rate calculation unit that calculates a flow rate on the basis of the temperatures measured by the temperature measurement units.

Provided are a system and a method for optimizing driving of an ultrasonic sensor. The system for optimizing driving of an ultrasonic sensor includes: an ultrasonic sensor unit provided on an inner bottom surface of a fuel tank for a vehicle and obtaining a time of flight (TOF) for calculating a distance from the inner bottom surface of the fuel tank to a fuel surface; and a central processing unit calculating liquid level information of the fuel tank using the TOF transferred from the ultrasonic sensor unit and controlling a driving voltage of the ultrasonic sensor unit using the liquid level information.

Methods and systems for managing characterization of wells using data acquisitions tools are disclosed. The data acquisition tools may be positioned in portions of wells. While positioned in the wells, the data acquisition tools may be measured. The measurements may be ingested into models and may provide, as output, inferred conditions in the portions of the wells. The models may be created using simulation systems. The simulation systems may allow for conditions that may be present in wells to be simulated, and data acquisition tools to be exposed to the simulated conditions. While exposed to the simulated conditions, the data acquisition tools may be measured to establish associations that may be used to infer conditions that may be present in wells.