A physical quantity measurement device measures a physical quantity of a fluid. A detection unit has a physical quantity detector that detects a physical quantity of the fluid in a measurement flow channel. A housing accommodates at least a part of the detection unit and forms the measurement flow channel. The housing includes a housing attachment that is attached to a predetermined attaching target, and a position holder holding a position of the detection unit by contacting the detection unit. The housing includes an inward part positioned inward of the attaching target and an outward part positioned outward of the attaching target. The position holder is provided inward of the housing attachment in an alignment direction along which the inward part and the outward part are aligned.

Methods and apparatuses associated with flow sensing devices are provided. An example flow sensing device may include a sensing element disposed at least partially within the housing, and a plurality of channels disposed within the housing defining a flow path configured to convey a flowing media through the flow sensing device, wherein the flow path is disposed proximate the sensing element such that at least a portion of the flowing media makes direct contact with the sensing element.

A fluid sensing apparatus includes a fluid sensor configured to detect a temperature distribution on a detection surface caused by heating, and output a signal value corresponding to a flow of a fluid; a falling time counting unit configured to count a falling time of the signal value after stopping the heating; and a failure determining unit configured to perform failure determination based on the falling time.

A thermal flowmeter including a measurement tube that has an inflow port into which a liquid flows and an outflow port that allows the liquid which flows in from the inflow port to flow out, and has an internal flow passage where the liquid flows formed to extend along an axis, and a plurality of detection sections each of which has a heating resistor and a temperature detecting resistor along the axis and is provided at the measurement tube, and a control section that calculates a flow rate of the liquid flowing through the internal flow passage based on signals from the plurality of detection sections, wherein the plurality of detection sections are respectively provided with predetermined intervals left in a circumferential direction with the axis as a center.

Described herein are thermal mass flow sensors that combine calorimetric and anemometric (e.g., hot-wire) elements to provide a hybrid approach to determining flow rate of a liquid. The flow probes or flow sensors are configured to use a heater to apply heat to a thermally-conducting material in contact with the flowing liquid, to measure a temperature of the thermally-conducting material upstream of the heater and downstream or at the heater, to adjust power to the heater to achieve a targeted temperature difference, and to determine a flow rate based at least in part on the power supplied to the heater and the measured temperatures. This approach provides flow rate due at least in part to the fluid cooling the thermally-conductive material proportionate to flow rate with non-linear effects. This hybrid approach can provide accurate readings of flow rates of liquids delivered through an IV line to a patient.

It is possible to suppress overcorrection.

A physical quantity detecting device includes: a physical quantity detecting sensor that detects a physical quantity of a measurement target fluid and outputs a detection signal; a compensation amount calculation unit that calculates, by using the detection signal, a lead compensation amount used in lead compensation for the detection signal; and a gain control unit that adjusts the lead compensation amount based on a deviation that is an amount of change in lead compensation amount over time.

A temperature sensor differs from a relative humidity sensor in responsiveness when the temperature of air changes. An absolute humidity acquisition unit acquires absolute humidity of air from outputs from the temperature sensor and the relative humidity sensor. A delay adjustment unit is to delay an output from one of the temperature sensor and the relative humidity sensor, which is a high response sensor having a higher responsiveness, and to reconcile change-behaviors of the output from the temperature sensor and the output from the relative humidity sensor in response to a temperature change in air. The absolute humidity acquisition unit acquires the absolute humidity based on the output from the other of the temperature sensor and the relative humidity sensor, which is a low response sensor having a lower responsiveness, and the sensor signal, which is from the high response sensor and delayed in the delay adjustment unit.

A method for determining a corrected air mass flow value in an engine having an air mass meter in its intake. The method includes determining a cold start condition of the engine at a first time when there is no air mass flow in the intake tract, producing a reference signal by the air mass meter at the first time, and determining an air mass flow offset from the reference signal, producing a measurement signal by the air mass meter at a second time, which is not equal to the first time, which is in an operating period of the engine, determining an air mass flow value from the measurement signal, and determining a corrected air mass flow value from the air mass flow offset and the air mass flow value.

Mass flow controllers and methods for correcting flow inconsistencies associated with parasitic flow of a fluid in mass flow controllers are disclosed. A method includes obtaining a pressure measurement signal of the fluid generated by a pressure sensor and receiving a flow sensor signal of the fluid generated by a flow sensor. An estimated parasitic flow signal is generated using the pressure measurement signal, and the flow sensor signal is accelerated to produce an accelerated flow sensor signal with a bandwidth that is comparable to that of the estimated parasitic flow signal. A corrected flow signal is generated using the accelerated flow sensor signal and the estimated parasitic flow signal to control the mass flow controller.

The flow rate measurement device according to one aspect of the present invention comprises a heating unit for heating a fluid; temperature sensing units that are provided flanking the heating unit in the direction of fluid flow, and that sense the temperature of the heated fluid; a flow rate calculation unit that calculates the flow rate of the fluid on the basis of a sensing signals outputted from the temperature sensing units; angle calculation unit for calculating the tilt angle of the temperature sensing units with respect to a specific reference plane; a storage unit that stores the relation between the flow rate, the tilt angle, and a flow rate correction value; and a flow rate correction unit that corrects the flow rate by using the flow rate correction value stored in the storage unit.