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.

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.

Various examples of methods and systems related to thermistor sensing for measurement of respiration are shown. In one example, a breath sensing system includes a self-heating temperature sensor that can be positioned in respiratory air of a subject and processing circuitry that can monitor operation of the self-heating temperature sensor. Respiratory information associated with physical or physiological properties of the subject can be communicated to a remotely located computing device. Electronic switching circuitry can be included to change operation of the self-heating temperature sensor between a temperature sensing mode and a heated power dissipation sensing mode. The processing circuitry can control switching between the modes. In another example, a method includes monitoring operational conditions of a self-heating temperature sensor positioned in respired air and determining, e.g., breath velocity, breath period, breath volume, breath carbon dioxide level, and heart rate based at least in part upon the operational conditions.

With respect to a vehicle mass air-flow sensor that includes a temperature sensor for measuring a temperature of a sensor element of the mass air-flow sensor, a method for controlling a heating element for heating the sensor element of a mass air-flow sensor includes identifying a dew formation on the sensor element by evaluating a temperature profile that is recorded during an operation of the vehicle using the temperature sensor, and generating a switch-on signal for switching on the heating element in response to the identification of the dew formation.

A gases flow rate sensing system may be configured to operate in at least two different target temperature modes, based upon a measured temperature of the gases flow. In some embodiments, the gases flow sensing system may have a voltage divider containing a thermistor. The gases flow rate may be determined based upon a voltage output indicating an amount of power needed to maintain the thermistor at a target temperature as specified by the target temperature mode, and a measured temperature of the gases flow.

A gases flow rate sensing system may be configured to operate in at least two different target temperature modes, based upon a measured temperature of the gases flow. In some embodiments, the gases flow sensing system may have a voltage divider containing a thermistor. The gases flow rate may be determined based upon a voltage output indicating an amount of power needed to maintain the thermistor at a target temperature as specified by the target temperature mode, and a measured temperature of the gases flow.

A fluid sensor for sensing a concentration or composition of a fluid, the sensor comprising: a semiconductor substrate comprising a first etched portion; a dielectric region located on the semiconductor substrate, wherein the dielectric region comprises a first dielectric membrane located over the first etched portion of the semiconductor substrate; a first heating element located within the first dielectric membrane; and a second heating element; wherein the first heating element is arranged to thermally shield the second heating element from ambient temperature changes; wherein the first heating element or the second heating element is configured to operate as a temperature sensing element; wherein the first heating element is configured to operate in a constant temperature or constant resistance mode; wherein the second heating element is configured to operate in a constant current or constant voltage mode or constant power mode; and wherein the sensor is configured to determine a thermal conductivity of the fluid using the temperature sensing element to determine said concentration or composition of the fluid.

The visibility of light is improved. A flow rate sensor device includes a substrate, sensor elements electrically connected to the substrate, light emitting elements positioned in a rear part of the sensor elements and disposed on a surface of the substrate, and light-transmissive cases internally accommodating the light emitting elements between the light-transmissive cases and the substrate. The light-transmissive cases have light diffusion members projecting from ceiling sections toward the light emitting elements, the light diffusion members have light incident surfaces facing the light emitting elements and wall surfaces connecting the light incident surfaces and the ceiling sections, and at least a part of the wall surfaces has a tilting surface having a dimension between the opposing wall surfaces, the dimension gradually increasing from a side close to the light incident surface toward the ceiling section.

It is an object to provide a flow rate sensor device having improved sensor responsiveness compared with the prior art. The present invention is a flow rate sensor device (1) including a sensor element (3, 4) that detects a flow rate, wherein a sensor unit (10) on which the sensor element (3, 4) is mounted and a drive substrate (11) including a drive control circuit are connected through a connection portion (12) narrower than a width of the drive substrate (11). Thus, a heat source in the drive substrate (11) and a heat source in the sensor unit (10) can be separated by the connection portion (12) that is thin in width, and the thermal influence from the drive substrate (11) to the sensor unit (10) can be suppressed. Therefore, good sensor responsiveness can be maintained.

It is an object to provide a flow rate sensor device having improved sensor responsiveness compared with the prior art. The present invention is a flow rate sensor device (1) including a sensor element (3, 4) that detects a flow rate, wherein a sensor unit (10) on which the sensor element (3, 4) is mounted and a drive substrate (11) including a drive control circuit are connected through a connection portion (12) narrower than a width of the drive substrate (11). Thus, a heat source in the drive substrate (11) and a heat source in the sensor unit (10) can be separated by the connection portion (12) that is thin in width, and the thermal influence from the drive substrate (11) to the sensor unit (10) can be suppressed. Therefore, good sensor responsiveness can be maintained.