Abstract: The method comprises producing a measurement signal (s1) having a signal parameter, followed with a temporal change (?x1/?t; ?x1?/?t) of a primary measured variable (x1) and a temporal change (?y1/?t) of a disturbing variable (?1), and producing a measurement signal (s2) having a signal parameter, followed by a temporal change (?x2/?t; ?x2?/?t) of a primary measured variable (x2). The method comprises ascertaining measured values (XI) of first type representing the primary measured variable (x1) or a secondary measured variable (f(x1) ?x1?) of measured values (XII) of second type representing the primary measured variable (x2) or a secondary measured variable (f(x2) ?x2?). The method comprises using measured values (XI) of first type and measured values (XII) of second type for ascertaining an error characterizing number (Err) representing a velocity error (?XI/?XII) caused by a change of the disturbing variable (y1).

Abstract: A sensing element is provided for use in a system for measuring fluid flow, such as, turbulent air flow. The sensing element comprises a sensor body and a first load cell arrangement connected to the sensor body. The sensor body has a three dimensional shape which is rotationally symmetric about a longitudinal axis passing through the first load cell arrangement and the sensor body. The first load cell arrangement is configured to measure the force exerted on the sensor body by fluid flow in at least an xy plane perpendicular to the longitudinal axis. A system for measuring fluid flow comprising the sensing element and a method for measuring fluid flow using the sensing element and the system are also provided.

Abstract: Disclosed is inter alia an apparatus (63) for sensing a movement of an object (10, 11) relative to a fluid (12, 13), e.g. for sensing relative movements of a surf board in water. A particular characteristic of the invention is that the housing (21) is mounted in fixed arrangement to a surface (20) of the object, the housing receiving a spring member (62) having a plurality of blades (25a, 25b, 25c, 25d), wherein each blade has an outer end (27) which is fixed to the housing, and an inner end (28) which is connecting to a center portion (65) of the spring, the plurality of blades defining a plane (73), wherein a plurality of strain gauges (26a, 26b, 26c, 26d) is positioned on the blades, and wherein a rigid pin (17) is mounted on the center portion of the spring member which is extending in a direction of a normal vector (74) of the plane and which is protruding from the surface (20) of the object and configured to dip into the fluid.

Abstract: Described are a two-dimensional wind-speed and wind-direction sensor and a system thereof, relating to the field of sensing devices. The two-dimensional wind-speed and wind-direction sensor includes: an X-direction wind speed probe assembly and a Y-direction wind speed probe assembly, the X-direction wind speed probe assembly and the Y-direction wind speed probe assembly are perpendicular to each other, and the X-direction wind speed probe assembly is configured to measure a X-direction wind speed including a wind speed in the reverse direction of an X-axis, Vx?, and a wind speed in the forward direction of the X-axis Vx+; and the Y-direction wind speed probe assembly is configured to measure a Y-direction wind speed including a wind speed in reverse direction of an Y-axis, Vy?, and a wind speed in the forward direction of the Y-axis, Vy+.

Abstract: Image data is used to determine wind speed and wind direction during takeoff and landing by an unmanned aerial vehicle (UAV). The flight data, including image data, may be received using sensors onboard the UAV and/or the flight data may be received from other sources, such as nearby anemometer, cameras, other UAVs, other vehicles, and/or local weather stations. Machine learning models may train using the flight data gathered by the UAVs to determine the wind velocity based on image data. The UAV may adjust flight control settings to generate side forces to overcome the predicted wind velocity.

Abstract: The invention relates to an instrument for measuring air speed by means of parabolic movement and to a measuring method, wherein the measuring instrument is formed by a cubic structure (1) that holds a screwable, flexible container (2) which releases—where air speed needs to be measured—a drop of liquid, the drop falling on one of the concentric circles located on an interchangeable plate (3) that is positioned on a flat base (4) of the device and perpendicular to the axial end of the outlet for the drop of liquid. Depending—on the height—the movement with which the drop falls, the air speed can be determined by means of the horizontal range of the parabolic movement followed by the drop of liquid, and evaluated using the distance between the point of impact of the drop on the surface with respect to the center.

Abstract: Thermal imaging devices, systems, and methods are provided with IR sensor amplification techniques that in some cases provide a gain transfer function having at least two different gain regions. One thermal imaging camera includes an IR camera module, processing circuitry, and an amplifier stage that comprises a continuous gain function including at least two gain regions having different gains. In some cases a thermal imager is provided with saturation circuitry configured to reduce the gain of the amplifier stage in order to provide one of at least two different gain regions within the continuous gain function. In some cases amplification techniques provide a continuous gain function that includes both linear and nonlinear gain regions. One or more gain regions may further be calibrated for measuring temperature.

Abstract: The invention relates to the use of a two-component composition comprising a polyol component and a polyisocyanate component, for producing flexible polyurethane gel coats for epoxy-resin and vinyl-ester resin composite materials.

Abstract: A device and method for applying a wind force to a plurality of plants in an agricultural environment is provided to screen for selected wind-resistance traits in the plurality of plants. In one embodiment of the present invention, a device is provided including a generating device for creating a moving fluid stream to provide the wind force, a directing device, such as a duct and/or movable vane, for precisely and selectively directing the wind force towards a portion of at least one plant, and a controller for adjusting one or more parameters of the fluid stream. The device and/or method embodiments of the present invention may thus be used to selectively apply the wind force to one or more plants (or portions thereof) such that the plants may be evaluated with respect to one or more wind-resistant physical characteristics.

Abstract: An aircraft performance degradation detection system may include information sources, a central unit connected to the information sources, and a warning device that is connected to the central unit. Using information received from the information sources, the central unit computes the current weight and drag of the aircraft and computes a theoretical drag based on the current weight. The current and theoretical drags are compared, and a determination is made regarding performance degradation based on the comparison.

Abstract: Wind indicator apparatus for indicating air flow comprising: a direction pointer, including a vane member, for providing a visible indication of air flow direction; pivoting means including a fixed portion for coupling to a sailing craft and a pivotable portion able to pivot with respect to said fixed portion and with which said direction pointer is entrained for movement therewith; and a counterbalance extending from said pivotable portion of said pivoting means and arranged to move therewith, the mass of the counterbalance being disposed so as to maintain the direction pointer in a substantially level position.

Abstract: The present invention concerns an apparatus for monitoring a wind power installation, with at least one sensor for detecting measurement values, and also a method of monitoring a wind power installation, in which: (i) a measurement value is detected with at least one sensor, (ii) the measurement value is converted into a signal representative of the measurement value, and (iii) the signal is stored and/or processed in accordance with a predetermined method. In one aspect, in order to provide an apparatus and a method which permit reliable detection of the loading on the pylon of the wind power installation, there is provided at least one sensor for detecting the loading on the pylon, the sensor being arranged in the region of the base of the pylon. In addition, the instantaneous loading on the wind power installation is ascertained from the signal representative of the measurement value ascertained by the sensor.

Abstract: The present invention concerns an apparatus for monitoring a wind power installation, with at least one sensor for detecting measurement values, and also a method of monitoring a wind power installation, in which a) a measurement value is detected with at least one sensor, b) said measurement value is converted into a signal representative of the measurement value, and c) the signal is stored and/or processed in accordance with a predetermined method. In order to provide an apparatus and a method which permit reliable detection of the loading on the pylon of the wind power installation, there is provided at least one sensor 20 for detecting the loading on the pylon 10, the sensor 20 being arranged in the region of the base of the pylon. In addition, the instantaneous loading on the wind power installation is ascertained from the signal representative of the measurement value ascertained by the sensor.

Abstract: A first cylinder drives a flap to a predetermined down position. Strain gages detect strains at each part of the flap while a load that corresponds to the down position is applied to the flap by a second cylinder that has been moved by an XY table so as to track the down position. Accordingly, actual aerodynamic forces are precisely reproduced by applying a load having a size and a direction that correspond to the down position of the flap. Thus, a stationary load test, a dynamic load test, and a durability test of the flap can be carried out automatically with a small effort and in a short time.

Abstract: A wind velocity measurement system employs two different principles of physics to measure wind speed: (1) the aerodynamic force imparted to a low profile, rigidly mounted cylindrical rod, and (2) the vibrating frequency of the rod as vortices are shed from the rod's cylindrical surface. A set of strain gages is used as a common sensor for both measurements, and these provide force measurements imparted by the wind on the rod. The signals generated by the strain gages are fed to processing circuitry that calculates the wind speed and direction from the signals. The force measurement is proportional to the square of the wind speed. Since it is a vector quantity, it can also be used to derive wind direction. The vortex shedding frequency is a scalar quantity and is linearly proportional to wind speed. This frequency can be calculated by analyzing the force measurements generated by the strain gages over time.