Provided is a thermal flow meter to improve the measurement accuracy of a temperature detector. The thermal flow meter includes a bypass passage through which a measurement target gas flowing through a main passage flows, and a circuit package which includes a measurement circuit for measuring a flow rate of the measurement target gas flowing through the bypass passage and a temperature detecting portion for detecting a temperature of the measurement target gas. The circuit package includes a circuit package body which is molded by a resin to internally envelope the measurement circuit and a protrusion molded by the resin. The temperature detecting portion is provided in the leading end portion of the protrusion, and at least the leading end portion of the protrusion protrudes to the outside from a housing.

A thermal flow sensor for determining flow of a medium, comprising: a substrate; first and second temperature sensors arranged on the substrate, wherein the first and second temperature sensors are embodied as heatable temperature sensors or as a first non-heatable temperature sensor, which is associated with a first heating element, and as a second non-heatable temperature sensor, which is associated with a second heating element; a power supply unit, which by means of a first signal supplies the first heatable temperature sensor or the first heating element with a first heating power determined earlier during an adjustment operation and by means of a second signal supplies the second heatable temperature sensor or the second heating element with a second heating power determined earlier in the adjustment operation; and an evaluation unit, which in a measurement operation for determining flow of the medium ascertains a temperature difference between the first temperature sensor and the second temperature sensor and based on the temperature difference determines a measured value, which represents the flow of the medium.

A thermal flow sensor for determining flow of a medium, comprising: a substrate; first and second temperature sensors arranged on the substrate, wherein the first and second temperature sensors are embodied as heatable temperature sensors or as a first non-heatable temperature sensor, which is associated with a first heating element, and as a second non-heatable temperature sensor, which is associated with a second heating element; a power supply unit, which by means of a first signal supplies the first heatable temperature sensor or the first heating element with a first heating power determined earlier during an adjustment operation and by means of a second signal supplies the second heatable temperature sensor or the second heating element with a second heating power determined earlier in the adjustment operation; and an evaluation unit, which in a measurement operation for determining flow of the medium ascertains a temperature difference between the first temperature sensor and the second temperature sensor and based on the temperature difference determines a measured value, which represents the flow of the medium.

To obtain a thermal flow meter capable of providing thermal insulation without degrading responsiveness of a temperature detection element. A thermal flow meter 300 of the present invention includes an air flow sensing portion 602 that detects a flow rate by performing heat transfer with a measurement target gas passing through the main passage 124 using a heat transfer surface, a temperature detection element 518 that detects a temperature of the measurement target gas, a circuit package 400 obtained by connecting a processing unit 604 that processes signals of the air flow sensing portion 602 and the temperature detection element 518 to a lead and sealing the processing unit 604 using a first molding resin through a first molding process, and a housing 302 where the circuit package 400 is fixed using a second molding resin through a second molding process, wherein, in the circuit package 400, a thickness of a temperature detecting portion 452 for sealing the temperature detection element 518 is thinner than that of a package body portion 426 for sealing the processing unit 604.

To obtain a thermal flow meter capable of providing thermal insulation without degrading responsiveness of a temperature detection element. A thermal flow meter 300 of the present invention includes an air flow sensing portion 602 that detects a flow rate by performing heat transfer with a measurement target gas passing through the main passage 124 using a heat transfer surface, a temperature detection element 518 that detects a temperature of the measurement target gas, a circuit package 400 obtained by connecting a processing unit 604 that processes signals of the air flow sensing portion 602 and the temperature detection element 518 to a lead and sealing the processing unit 604 using a first molding resin through a first molding process, and a housing 302 where the circuit package 400 is fixed using a second molding resin through a second molding process, wherein, in the circuit package 400, a thickness of a temperature detecting portion 452 for sealing the temperature detection element 518 is thinner than that of a package body portion 426 for sealing the processing unit 604.

A wind speed measuring device includes a constant temperature heat generating device that generates heat at a predetermined set temperature. The constant temperature heat generating device includes a power source, a heat generating element, a switching element, a comparator element, a first negative characteristic thermistor element, and a plurality of resistance elements. The heat generating element and the first negative characteristic thermistor element define a wind speed sensor. The switching element repeats turning on and off to make the heat generating element generate heat at a predetermined set temperature. A pulse voltage is applied from the power source to the heat generating element. A wind speed of a wind contacted with the wind speed sensor is calculated based on a wave form of the applied pulse voltage.

A wind speed measuring device includes a constant temperature heat generating device that generates heat at a predetermined set temperature. The constant temperature heat generating device includes a power source, a heat generating element, a switching element, a comparator element, a first negative characteristic thermistor element, and a plurality of resistance elements. The heat generating element and the first negative characteristic thermistor element define a wind speed sensor. The switching element repeats turning on and off to make the heat generating element generate heat at a predetermined set temperature. A pulse voltage is applied from the power source to the heat generating element. A wind speed of a wind contacted with the wind speed sensor is calculated based on a wave form of the applied pulse voltage.

A collar is provided for use with a fluid flow sensor to reduce condensation of a moist gas flowing through the fluid flow sensor. The collar comprises a body defining an interior that defines an airspace between the collar and the housing of the fluid flow sensor when the collar is positioned on the fluid flow sensor. The collar also includes a heat source secured to the body and adapted to heat air contained within the airspace to consequently heat the housing of the fluid flow sensor and the interior surfaces of the sensor to reduce condensation of the moist gas.

A collar is provided for use with a fluid flow sensor to reduce condensation of a moist gas flowing through the fluid flow sensor. The collar comprises a body defining an interior that defines an airspace between the collar and the housing of the fluid flow sensor when the collar is positioned on the fluid flow sensor. The collar also includes a heat source secured to the body and adapted to heat air contained within the airspace to consequently heat the housing of the fluid flow sensor and the interior surfaces of the sensor to reduce condensation of the moist gas.

A sensor comprises a substrate having a first surface; a cap structure connected to the substrate, the cap structure configured to define a cavity between an inner surface of the cap structure and the first surface of the substrate, the cap structure configured to block infrared radiation from entering the cavity from outside the cap structure; a plurality of absorbers, each absorber in the plurality of absorbers being connected to the first surface of the substrate and arranged at a respective position within the cavity and configured to absorb infrared radiation at the respective position within the cavity; and a plurality of readout circuits, each readout circuit in the plurality of readout circuits being connected to a respective absorber in the plurality of absorbers and configured to provide a measurement signal that indicates an amount of infrared radiation absorbed by the respective absorber.