Abstract: A physical quantity measurement device for measuring a physical quantity of a fluid includes a housing that includes a bypass flow channel through which a fluid flows and a physical quantity detection unit that detects a physical quantity of the fluid in the bypass flow channel. The housing includes a housing main body made of a dielectric and a covering film that covers at least a part of a surface of the housing main body, and the surface of the housing is positive charged due to positive charges being arranged in the housing main body along the surface of the housing main body or the positive charges being arranged in the covering film along a surface of the covering film.

Abstract: A sensor device is disposed in an intake passage through which intake air flows to an internal combustion engine. The sensor device includes a humidity sensor that generates a signal according to a humidity of the intake air flowing through the intake passage. A choke portion is defined in the intake passage to decrease a cross-sectional area of the intake passage. The humidity sensor is arranged on the choke portion.

Abstract: A physical quantity measurement device for measuring a physical quantity of a fluid includes a housing that includes a bypass flow channel through which a fluid flows and a physical quantity detection unit that detects a physical quantity of the fluid in the bypass flow channel. The housing includes a housing main body made of a dielectric and a covering film that covers at least a part of a surface of the housing main body, and the surface of the housing is positive charged due to positive charges being arranged in the housing main body along the surface of the housing main body or the positive charges being arranged in the covering film along a surface of the covering film.

Abstract: An air flow rate adjusting apparatus adjusts an output of an air flow meter based on a dimension of a gap between a back surface of a sensor chip and a bottom surface of a recess of a support plate.

Abstract: A sensor device is disposed in an intake passage through which intake air flows to an internal combustion engine. The sensor device includes a humidity sensor that generates a signal according to a humidity of the intake air flowing through the intake passage. A choke portion is defined in the intake passage to decrease a cross-sectional area of the intake passage. The humidity sensor is arranged on the choke portion.

Abstract: A sensor device is disposed in an intake passage through which intake air flows to an internal combustion engine. The sensor device includes a humidity sensor that generates a signal according to a humidity of the intake air flowing through the intake passage. A choke portion is defined in the intake passage to decrease a cross-sectional area of the intake passage. The humidity sensor is arranged on the choke portion.

Abstract: A sensor device is disposed in an intake passage through which intake air flows to an internal combustion engine. The sensor device includes a humidity sensor that generates a signal according to a humidity of the intake air flowing through the intake passage. A choke portion is defined in the intake passage to decrease a cross-sectional area of the intake passage. The humidity sensor is arranged on the choke portion.

Abstract: A sensor device is disposed in an intake passage through which intake air flows to an internal combustion engine. The sensor device includes a humidity sensor that generates a signal according to a humidity of the intake air flowing through the intake passage. A choke portion is defined in the intake passage to decrease a cross-sectional area of the intake passage. The humidity sensor is arranged on the choke portion.

Abstract: An air flow rate adjusting apparatus adjusts an output of an air flow meter based on a dimension of a gap between a back surface of a sensor chip and a bottom surface of a recess of a support plate.

Abstract: An air flow rate adjusting apparatus adjusts an output of an air flow meter based on a dimension of a gap between a back surface of a sensor chip and a bottom surface of a recess of a support plate.

Abstract: A sensor device is disposed in an intake passage through which intake air flows to an internal combustion engine. The sensor device includes a humidity sensor that generates a signal according to a humidity of the intake air flowing through the intake passage. A choke portion is defined in the intake passage to decrease a cross-sectional area of the intake passage. The humidity sensor is arranged on the choke portion.

Abstract: An air flow rate adjusting apparatus adjusts an output of an air flow meter based on a dimension of a gap between a back surface of a sensor chip and a bottom surface of a recess of a support plate.

Abstract: When a deterioration determination apparatus determines a degree of deterioration in characteristics of an airflow meter, a driving condition of an engine is maintained at a specified condition in which intake air flow rate is greater than a specified value. A measurement error of the airflow meter is computed based on an intake air flow rate measured with the airflow meter. The degree of deterioration due to stain is determined based on the measurement error.

Abstract: An air flow measuring device includes a measured passage and a sensor portion. Measured air which is a measuring object flows through the measured passage. The sensor portion is disposed in a sensor arrangement portion of the measured passage and is configured to measure a flow rate of measured air flowing through the measured passage. The measured passage includes an upstream bent portion on an upstream side of the sensor arrangement portion in a flow direction of measured air. The upstream bent portion includes an upstream throttle that partly decreases a passage area of the measured passage.

Abstract: An air flow rate measuring apparatus includes a heater and a control circuit. The heater heats a part of an intake air sucked into an engine. The control circuit controls an energization of the heater. The heater has a measuring-mode temperature when a flow rate of the intake air is measured. The control circuit has a heat cleaner which temporarily raises a temperature of the heater higher than the measuring-mode temperature when an energization of the air flow rate measuring apparatus is started.

Abstract: An air flow rate measuring apparatus includes a heater and a control circuit. The heater heats a part of an intake air sucked into an engine. The control circuit controls an energization of the heater. The heater has a measuring-mode temperature when a flow rate of the intake air is measured. The control circuit has a heat cleaner which temporarily raises a temperature of the heater higher than the measuring-mode temperature when an energization of the air flow rate measuring apparatus is started.

Abstract: An air flow measuring device includes a measured passage and a sensor portion. Measured air which is a measuring object flows through the measured passage. The sensor portion is disposed in a sensor arrangement portion of the measured passage and is configured to measure a flow rate of measured air flowing through the measured passage. The measured passage includes an upstream bent portion on an upstream side of the sensor arrangement portion in a flow direction of measured air. The upstream bent portion includes an upstream throttle that partly decreases a passage area of the measured passage.

Abstract: When a deterioration determination apparatus determines a degree of deterioration in characteristics of an airflow meter, a driving condition of an engine is maintained at a specified condition in which intake air flow rate is greater than a specified value. A measurement error of the airflow meter is computed based on an intake air flow rate measured with the airflow meter. The degree of deterioration due to stain is determined based on the measurement error.