A sensor includes a heater, a thermal insulator between two thermometer layers, the heater generating a thermal gradient within the thermal insulator. The thermometers give an indirect measurement of fluid flow around the sensor, based on their temperature readings. The thermometers are flexible layers including gels.

An apparatus for measuring airflow in an airstream includes a generally planar panel adapted to be placed in the airstream so that air passes over opposite surfaces of the panel. The panel includes at least one slot that extends through the panel. A hot-point element is mounted on one of the panel surfaces adjacent the at least one slot. The at least one slot is configured to permit air passing over the opposite surfaces to pass through the slot and become mixed together. The hot-point element is positioned on the panel so that the mixed air passes over the hot-point element.

An apparatus for measuring airflow in an airstream includes a generally planar panel adapted to be placed in the airstream so that air passes over opposite surfaces of the panel. The panel includes at least one slot that extends through the panel. A hot-point element is mounted on one of the panel surfaces adjacent the at least one slot. The at least one slot is configured to permit air passing over the opposite surfaces to pass through the slot and become mixed together. The hot-point element is positioned on the panel so that the mixed air passes over the hot-point element.

A sensor unit for use in the multiphase flow of a harvesting machine, wherein the sensor unit exhibits sensors for transmitting and/or receiving electromagnetic radiation. In addition, the sensor unit has at least one device for acquiring flow parameters of the multiphase flow. The measuring values of the sensor unit can advantageously be used for controlling the operating mode of the harvesting machine.

An airflow velocity measuring apparatus that includes a fixed-temperature heat generating device. The fixed-temperature heat generating device includes a power supply, a positive-temperature-coefficient thermistor element, a switching element, a comparator element, a first negative-temperature-coefficient thermistor element, a second negative-temperature-coefficient thermistor element, and plural resistor elements. The positive-temperature-coefficient thermistor element is disposed at a measuring point at which the velocity of airflow is measured. The switching element is repeatedly turned ON and OFF so as to cause the positive-temperature-coefficient thermistor element to generate heat at a preset temperature, thereby applying a pulse voltage from the power supply to the positive-temperature-coefficient thermistor element. The airflow velocity measuring apparatus measures the velocity of airflow at the measuring point based on the waveform of this pulse voltage. Adding of a second switch makes it possible to correct measurement errors caused by a rise or a fall in the temperature of subject airflow.

An airflow velocity measuring apparatus that includes a fixed-temperature heat generating device. The fixed-temperature heat generating device includes a power supply, a positive-temperature-coefficient thermistor element, a switching element, a comparator element, a first negative-temperature-coefficient thermistor element, a second negative-temperature-coefficient thermistor element, and plural resistor elements. The positive-temperature-coefficient thermistor element is disposed at a measuring point at which the velocity of airflow is measured. The switching element is repeatedly turned ON and OFF so as to cause the positive-temperature-coefficient thermistor element to generate heat at a preset temperature, thereby applying a pulse voltage from the power supply to the positive-temperature-coefficient thermistor element. The airflow velocity measuring apparatus measures the velocity of airflow at the measuring point based on the waveform of this pulse voltage. Adding of a second switch makes it possible to correct measurement errors caused by a rise or a fall in the temperature of subject airflow.

The present invention provides an apparatus adapted to survey a predetermined characteristic within a body of fluid adjacent an axis that transects the body of fluid, the apparatus comprising: a survey member interposed between first and second position defining arrangements; and at least one instrumentality associated with the survey member, each instrumentality adapted to survey the predetermined characteristic of the body of fluid adjacent the axis, wherein a survey of the predetermined characteristic is conducted over a predetermined time period. The present invention provides a method of surveying a predetermined characteristic within a body of fluid adjacent an axis that transects the body of fluid, the method comprising the steps of: deploying into a body of fluid at least one apparatus according to the first aspect of the invention; and obtaining survey data of the predetermined characteristic from one or more of the instrumentalities over the predetermined time period. The present invention also provides methods of determining whether a potentially suitable site is a suitable site for operative location of a fluid-based electricity generator, and other related methods.

The present invention provides an apparatus adapted to survey a predetermined characteristic within a body of fluid adjacent an axis that transects the body of fluid, the apparatus comprising: a survey member interposed between first and second position defining arrangements; and at least one instrumentality associated with the survey member, each instrumentality adapted to survey the predetermined characteristic of the body of fluid adjacent the axis, wherein a survey of the predetermined characteristic is conducted over a predetermined time period. The present invention provides a method of surveying a predetermined characteristic within a body of fluid adjacent an axis that transects the body of fluid, the method comprising the steps of: deploying into a body of fluid at least one apparatus according to the first aspect of the invention; and obtaining survey data of the predetermined characteristic from one or more of the instrumentalities over the predetermined time period. The present invention also provides methods of determining whether a potentially suitable site is a suitable site for operative location of a fluid-based electricity generator, and other related methods.

Proposed is an air velocity sensor (meter) for measuring the flow velocity of a fluid, particularly, the air velocity of gas. More specifically, proposed is a technical field related to an air velocity sensor which measures air velocity or temperature through the heat transfer of a fluid by using a hot wire, that is, a heating element, of a small cross-section, and which expands the surface areas of a temperature sensor, the heating element, and a soldering part in order to further improve the accuracy of a hot wire flow velocity sensor having higher accuracy, even with respect to a low flow velocity, than a general mechanical anemometer, so as to minimize resistance, and thus can easily measure very low flow rates by inducing a quick change in a current to quickly respond to minute changes in resistance and sensitively operate, that is, by improving reaction speed.

Proposed is an air velocity sensor (meter) for measuring the flow velocity of a fluid, particularly, the air velocity of gas. More specifically, proposed is a technical field related to an air velocity sensor which measures air velocity or temperature through the heat transfer of a fluid by using a hot wire, that is, a heating element, of a small cross-section, and which expands the surface areas of a temperature sensor, the heating element, and a soldering part in order to further improve the accuracy of a hot wire flow velocity sensor having higher accuracy, even with respect to a low flow velocity, than a general mechanical anemometer, so as to minimize resistance, and thus can easily measure very low flow rates by inducing a quick change in a current to quickly respond to minute changes in resistance and sensitively operate, that is, by improving reaction speed.