Abstract: A physical quantity measurement device includes a housing forming a measurement flow path through which the fluid flows and a container space that houses a part of a detection unit. An inner surface of the housing includes a housing intersecting surface that intersects an arrangement direction in which the measurement flow path and the container space are arranged, a housing flow path surface extending from the housing intersecting surface toward the measurement flow path, and a housing container surface extending from the housing intersecting surface toward the container space. The housing includes a housing partition that protrudes from the inner surface toward the detection unit and contacts the detection unit between the housing and the detection unit such that the housing partition separates the measurement flow path and the container space from each other.

Abstract: An air flow rate measurement device includes a flow rate detection unit, a detected flow rate response compensation unit, a pulsation amplitude calculation unit, a correction value calculation unit, and an error correction unit. The flow rate detection unit detects a detected flow rate. The detected flow rate response compensation unit advances a response time of the detected flow rate and calculating a compensation flow rate which is an output obtained by compensating for a response delay of the detected flow rate. The pulsation amplitude calculation unit calculates a pulsation amplitude correlated with a pulsation amplitude in the detected flow rate. The correction value calculation unit calculates a pulsation correction value which is a value for correcting the compensation flow rate based on the pulsation amplitude. The error correction unit corrects the compensation flow rate based on the pulsation correction value.

Abstract: A physical quantity measurement device includes a housing forming a measurement flow path in which a sensor support supports a physical quantity sensor. The measurement flow path includes a sensor path in which the physical quantity sensor is disposed, an upstream curved path between the sensor path and an inlet, and a downstream curved path between the sensor path and an outlet. The housing includes a measurement narrowed portion that gradually narrows the measurement flow path in a direction from the inlet toward the physical quantity sensor. An upstream end of the sensor support is provided upstream of the measurement narrowed portion in an arrangement cross section along an imaginary straight line passing through the physical quantity sensor and extending in an arrangement direction in which the upstream curved path and the downstream curved path are arranged.

Abstract: A physical quantity measurement device includes a housing forming a measurement flow path including a measurement inlet and a measurement outlet. The measurement flow path includes a sensor path in which a physical quantity sensor is disposed, an upstream curved path curved to extend from the sensor path toward the measurement inlet, and a downstream curved path curved to extend from the sensor path toward the measurement outlet. An inner surface of the housing includes an upstream outer curved surface that defines an outer outline of a curved part of the upstream curved path, and a downstream outer curved surface that defines an outer outline of a curve part of the downstream curved path. A degree of recess of the downstream outer curved surface is larger than a degree of recess of the upstream outer curved surface.

Abstract: A physical quantity measurement device includes a housing forming a through flow path, and a measurement flow path branching from the through flow path. A physical quantity sensor is provided in the measurement flow path. An inner surface of the housing includes an inlet ceiling surface and an inlet floor surface which face each other and define an inlet through path that is between and connects an inlet of the through flow path and an inlet of the measurement flow path, The inlet ceiling surface includes a ceiling inclined surface that extends from the inlet of the through flow path and is inclined with respect to the inlet floor surface. A distance between the ceiling inclined surface and the inlet floor surface gradually decreases in a direction from the inlet of the through flow path toward an outlet of the through flow path.

Abstract: A humidity measurement device is configured to measure a humidity of a gas. The humidity measurement device includes: a second-order calculation part to calculate a second-order differential value by performing second-order differentiation by time on a humidity signal output from a humidity detection part; and an adherence determination part to determine whether a liquid has adhered to the humidity detection part based on the second-order differential value obtained by the second-order calculation part.

Abstract: A temperature sensor and a relative humidity sensor are placed in an environment allowing air to flow and are displaced in an upstream-downstream direction of the airflow. 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 delays an output from one of the temperature sensor and the relative humidity sensor placed upstream and to reconcile change-behaviors of outputs from the temperature sensor and the relative humidity sensor in response to a state 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 placed downstream and an output acquired from the one sensor placed upstream and delayed in the delay adjustment unit.

Abstract: 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.

Abstract: A measurement control device measures an air flow rate using an output value of a sensing portion that outputs a signal according to the air flow rate, and outputs the measurement result of the air flow rate to a predetermined external device. The measurement control device includes: a pulsation state calculator that calculates a pulsation state, which is a state of pulsation generated in the air flow rate, by using the output value of the sensing portion instead of acquiring an output value from an external device; and a flow rate correcting unit that corrects the air flow rate using the pulsation state calculated by the pulsation state calculator.

Abstract: A physical quantity measurement device includes a housing forming a measurement flow path through which the fluid flows and a container space that houses a part of a detection unit. An inner surface of the housing includes a housing intersecting surface that intersects an arrangement direction in which the measurement flow path and the container space are arranged, a housing flow path surface extending from the housing intersecting surface toward the measurement flow path, and a housing container surface extending from the housing intersecting surface toward the container space. The housing includes a housing partition that protrudes from the inner surface toward the detection unit and contacts the detection unit between the housing and the detection unit such that the housing partition separates the measurement flow path and the container space from each other.

Abstract: A physical quantity measurement device includes a housing forming a measurement flow path, a physical quantity sensor that detects a physical quantity of fluid in the measurement flow path, and a sensor support that supports the physical quantity sensor. The sensor support includes a support front surface on which the physical quantity sensor is disposed, and a support back surface behind the support front surface. The housing includes a floor surface facing a support end of the sensor support, a front wall surface facing the support front surface, and a back wall surface opposite to the front wall surface across the floor surface and facing the support back surface. A front distance between the physical quantity sensor and the front wall surface in a front-back direction is larger than a floor distance between the floor surface and the support end in a height direction orthogonal to the front-back direction.

Abstract: A physical quantity measurement device includes a housing forming a measurement flow path including a measurement inlet and a measurement outlet. The measurement flow path includes a sensor path in which a physical quantity sensor is disposed, an upstream curved path curved to extend from the sensor path toward the measurement inlet, and a downstream curved path curved to extend from the sensor path toward the measurement outlet. An inner surface of the housing includes an upstream outer curved surface that defines an outer outline of a curved part of the upstream curved path, and a downstream outer curved surface that defines an outer outline of a curve part of the downstream curved path. A degree of recess of the downstream outer curved surface is larger than a degree of recess of the upstream outer curved surface.

Abstract: A physical quantity measurement device includes a housing forming a through flow path, and a measurement flow path branching from the through flow path. A physical quantity sensor is provided in the measurement flow path. An inner surface of the housing includes an inlet ceiling surface and an inlet floor surface which face each other and define an inlet through path that is between and connects an inlet of the through flow path and an inlet of the measurement flow path, The inlet ceiling surface includes a ceiling inclined surface that extends from the inlet of the through flow path and is inclined with respect to the inlet floor surface. A distance between the ceiling inclined surface and the inlet floor surface gradually decreases in a direction from the inlet of the through flow path toward an outlet of the through flow path.

Abstract: A physical quantity measurement device includes a housing forming a measurement flow path in which a sensor support supports a physical quantity sensor. The measurement flow path includes a sensor path in which the physical quantity sensor is disposed, an upstream curved path between the sensor path and an inlet, and a downstream curved path between the sensor path and an outlet. The housing includes a measurement narrowed portion that gradually narrows the measurement flow path in a direction from the inlet toward the physical quantity sensor. An upstream end of the sensor support is provided upstream of the measurement narrowed portion in an arrangement cross section along an imaginary straight line passing through the physical quantity sensor and extending in an arrangement direction in which the upstream curved path and the downstream curved path are arranged.

Abstract: An air flow rate measurement device includes a flow rate detection unit, a detected flow rate response compensation unit, a pulsation amplitude calculation unit, a correction value calculation unit, and an error correction unit. The flow rate detection unit detects a detected flow rate. The detected flow rate response compensation unit advances a response time of the detected flow rate and calculating a compensation flow rate which is an output obtained by compensating for a response delay of the detected flow rate. The pulsation amplitude calculation unit calculates a pulsation amplitude correlated with a pulsation amplitude in the detected flow rate. The correction value calculation unit calculates a pulsation correction value which is a value for correcting the compensation flow rate based on the pulsation amplitude. The error correction unit corrects the compensation flow rate based on the pulsation correction value.

Abstract: A physical quantity measurement device includes a measurement channel through which the fluid flows to be measured, a physical quantity detector that detects a physical quantity of a fluid in the measurement channel, a housing forming the measurement channel, and a measurement outlet provided in the housing as a downstream end of the measurement channel. An outer peripheral surface of the housing includes an outer peripheral flat surface that extends in an arrangement direction along which an upstream end and a downstream end of the housing are arranged, and an outer peripheral inclined surface inclined with respect to the outer peripheral flat surface and provided between the upstream end and the outer peripheral flat surface in the arrangement direction. The measurement outlet is positioned upstream of the downstream end of the housing.

Abstract: A sensor assembly includes a sensor portion and a sensor circuit, which are integrated with each other and configured to measure an air flow quantity. A thermistor is configured to measure an air temperature. A metal plate includes a grounding end terminal. One lead wire of the thermistor is joined electrically with the grounding end terminal. The sensor circuit is disposed on the metal plate. The sensor circuit is entirely overlapped with the plate shape portion in a direction perpendicular to the metal plate.

Abstract: An air flow rate measuring device measures an air flow rate based on an output value of a sensing unit placed in an environment that allows air to flow therethrough. The air flow rate measuring device includes: an acquisition unit configured to acquire the output value; a storage unit configured to store uneven flow information that indicates an uneven flow state of the air in the environment; a pulsation error correction unit configured to correct the air flow rate by using at least one of the uneven flow information and the output value such that the pulsation error Err in the air flow rate caused by the uneven flow becomes smaller.

Abstract: A temperature sensor and a relative humidity sensor are placed in an environment allowing air to flow and are displaced in an upstream-downstream direction of the airflow. 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 delays an output from one of the temperature sensor and the relative humidity sensor placed upstream and to reconcile change-behaviors of outputs from the temperature sensor and the relative humidity sensor in response to a state 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 placed downstream and an output acquired from the one sensor placed upstream and delayed in the delay adjustment unit.

Abstract: 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.