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.

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.

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 thermal flowmeter comprises a heating element thermally coupled to a flowing medium, a first temperature sensor and second temperature sensor. The first temperature sensor detects a flowing medium temperature in a region not affected by the heating element. The second temperature sensor detects a temperature of the heating element and also serves as a heating element. A control unit controls heating power of the heating element based on the difference between the detected temperatures at a predetermined time. The control unit provides a square wave signal to the second temperature sensor so that in a high phase it acts as heating element and in a low phase as a temperature sensor.

A thermal flowmeter comprises a heating element thermally coupled to a flowing medium, a first temperature sensor and second temperature sensor. The first temperature sensor detects a flowing medium temperature in a region not affected by the heating element. The second temperature sensor detects a temperature of the heating element and also serves as a heating element. A control unit controls heating power of the heating element based on the difference between the detected temperatures at a predetermined time. The control unit provides a square wave signal to the second temperature sensor so that in a high phase it acts as heating element and in a low phase as a temperature sensor.

A medical device, for example, an anesthesia apparatus or ventilator, including a hot wire sensor (10); a hot wire sensor (10) and a hot wire module (14) for a hot wire sensor (10) are provided. A first hot wire and a second hot wire (26, 28), namely, a measuring wire (26) and a compensation wire (28), are connectable to the hot wire sensor (10), for example, in the form of a hot wire module (14), in an electrically conductive manner. A first contact pair (52, 54) is associated with the measuring wire (26) for contacting same and a second contact pair (56, 58) is associated with the compensation wire (28) for contacting same. The contacts of the second contact pair (56, 58) are configured as leading contacts in relation to at least one of the contacts of the first contact pair (52, 54).

A thermal flowmeter includes a tube, a temperature measuring device disposed on the tube and detecting a first temperature of a fluid, a heating and temperature measuring device disposed on the tube and detecting a second temperature of the fluid, a controller causing the heating and temperature measuring device to generate heat, a power determining unit determining a power consumption of the heating and temperature measuring device, a flow rate obtaining unit converting the power consumption into a flow rate, a flow rate correcting unit correcting the flow rate, a memory unit storing a first zero-point power consumption, a zero-point power ratio calculating unit calculating a zero-point power ratio based on the first zero-point power consumption and a second zero-point power consumption, and a setting unit calculating a correction factor based on the zero-point power ratio and setting the correction factor in the flow rate correcting unit.

A thermal flowmeter includes a tube, a temperature measuring device disposed on the tube and detecting a first temperature of a fluid, a heating and temperature measuring device disposed on the tube and detecting a second temperature of the fluid, a controller causing the heating and temperature measuring device to generate heat, a power determining unit determining a power consumption of the heating and temperature measuring device, a flow rate obtaining unit converting the power consumption into a flow rate, a flow rate correcting unit correcting the flow rate, a memory unit storing a first zero-point power consumption, a zero-point power ratio calculating unit calculating a zero-point power ratio based on the first zero-point power consumption and a second zero-point power consumption, and a setting unit calculating a correction factor based on the zero-point power ratio and setting the correction factor in the flow rate correcting unit.

Provided is a technique capable of more accurately measuring and outputting a flow rate according to an intended purpose, in a flow rate measurement device. A flow rate measurement device (1) for detecting a flow rate of measurement target fluid flowing through a main flow path (2) includes: a heater (113) configured to heat measurement target fluid; a plurality of temperature detectors (111, 112) that are arranged with the heater interposed in between in a flow direction of the measurement target fluid, and are configured to detect a temperature of the measurement target fluid; and a converter (133) configured to convert a difference in outputs of the plurality of temperature detectors into a heat flow rate or a heat quantity of measurement target fluid flowing through the main flow path.

Provided is a technique capable of more accurately measuring and outputting a flow rate according to an intended purpose, in a flow rate measurement device. A flow rate measurement device (1) for detecting a flow rate of measurement target fluid flowing through a main flow path (2) includes: a heater (113) configured to heat measurement target fluid; a plurality of temperature detectors (111, 112) that are arranged with the heater interposed in between in a flow direction of the measurement target fluid, and are configured to detect a temperature of the measurement target fluid; and a converter (133) configured to convert a difference in outputs of the plurality of temperature detectors into a heat flow rate or a heat quantity of measurement target fluid flowing through the main flow path.