How to measure wind speed How to measure wind speed

The level 0 smoke column goes straight to the sky, and the level 1 green smoke deviates with the wind.

Level 2 wind blows the face, level 3 leaves move the red flag.

Level 4 winds blow off pieces of paper, and level 5 small trees with leaves shake.

Level 6 is difficult to walk with an umbrella, and Level 7 is inconvenient to walk against the wind.

Level 8 winds blow tree branches and break branches, and level 9 roof tiles fly up.

Level 10 uprooting trees and falling houses, rare on land, and seen at sea.

Explanation: Level 0 - No wind, quiet, smoke straight up, Level 0 (m s) Level 1 - soft wind, smoke can indicate direction, but the wind vane cannot be rotated, Level 2 - light wind, the human face feels the wind, the leaves are slightly sounding, the ordinary weather vane turns, Level 3 - breeze, leaves and twigs swaying, flag, Level 4 - wind, can blow dust and paper on the ground, the twigs of the tree shake, Level 5 - breeze, small trees swaying, Level 6 - strong wind, large branches shaking, power lines whirring, difficulty holding umbrellas, Level 7 - wind, Big trees shake, windward walking feels inconvenient, level 8 - strong wind, broken branches, windward walking feels very resistant, level 9 - gale, chimneys and flat roofs are damaged (chimney tops and flat roofs shake), level 10 - strong winds, rare on land, can be uprooted and destroyed houses, level 11 - storms, rare on land, some will be heavily damaged, 12 - hurricanes, rarely on land, their destructive power is extremely large, above (m s).

A piece of shredded paper, let it fall freely in a windy area, measure the time and horizontal displacement, and the wind speed can be known approximately, but because the aerodynamic force and the shredded paper have fluid equations, it must not be very accurate, just rough.

How far can float when loosened from a certain height with shredded paper can be calculated with the formula of the flat throwing motion.

Determination of wind speed.

Commonly used instruments are cup anemometers, wing anemometers, catarrhal thermometers, and thermobulby electric anemometers. Wing and cup anemometers are easy to use, but they are only suitable for measuring large wind speeds due to their inert and mechanical friction resistance.

Thermobulby electric anemometer.

1.Construction principle.

It is an instrument that can measure low wind speed, and its measurement range is: It is composed of two parts: a hot bulby rod probe and a measuring instrument. The probe has a diameter glass sphere with a nickel-chromium wire coil for heating the glass sphere and two thermocouples connected in series.

The cold end of the thermocouple is attached to a phosphor copper pillar and is directly exposed to the air flow. When a certain amount of electric current passes through the heating ring, the temperature of the glass sphere increases. The degree of elevation is related to the wind speed, and the degree of elevation of the wind speed is large when the wind speed is small; Conversely, the degree of elevation is small.

The magnitude of the elevation is indicated by a thermocouple on the meter. According to the reading of the meter, check the correction curve, and the wind speed (m s) can be found.

2.How to use:

Before use, observe whether the pointer of the meter is pointing to the zero point, if there is an offset, you can gently adjust the mechanical adjustment screw of the meter to make the pointer return to the zero point;

Place the correction switch in the off position;

Plug the stem plug into the socket, place the rod vertically upward, press the plug to seal the probe, and place the "correction switch" in the full position, and slowly adjust the "full adjustment" knob so that the meter pointer points to the full position;

Put the "correction switch" in the "zero position", and slowly adjust the two knobs of "coarse adjustment" and "fine adjustment" so that the meter pointer points to the position of the zero point;

After the above steps, gently pull the screw plug to expose the rod probe (the length can be selected according to needs), and make the red dot on the probe face the wind direction, according to the meter degree reading, check the correction curve, and the measured wind speed can be detected;

After measuring a number of minutes (about 10min), the above steps must be repeated once to standardize the current in the instrument; After the measurement, the "correction switch" should be placed in the broken position.

3.Precautions.

This instrument is a more sophisticated instrument, which is strictly protected from collision and vibration, and cannot be used in places with excessive dust content or corrosiveness.

The instrument is equipped with 4 batteries, which are divided into two groups, one with three cells in series, and one with a single cell. When adjusting the "full adjustment" knob, if the meter cannot reach the full scale, it means that the single battery has been exhausted; When adjusting the "coarse adjustment" and "fine adjustment" knobs, if the meter pointer cannot return to the zero point, it means that the three batteries have been exhausted; When replacing the battery, open the small door at the bottom of the instrument and connect it in the correct direction.

After the instrument is repaired, it must be recalibrated.

Hope mine is helpful to you

There are roughly three methods for measuring air volume by anemometer: rotary anemometer, differential pressure anemometer, and ** anemometer. Before use, to check whether the anemometer fan can operate normally, the size of the measured air outlet and air duct must be measured on the spot.

The air volume is determined by the product of the uniform wind speed of the tuyere cross-section and the net cross-sectional area of the tuyere.

Anemometer method for measuring air volume

Rotary anemometer: also known as rotary anemometer, consists of a three-bladed or four-bladed propeller composed of an induction part, which is installed at the front end of the wind vane, so that it is aimed at the direction of the wind at any time.

Differential pressure anemometer: It is the use of the difference between the total pressure and the static pressure of the wind to determine the size of the wind speed, the head hole and the side wall hole are connected to the two ends of the differential pressure gauge respectively, according to the differential pressure gauge reading and the use of relevant formulas to calculate, you can obtain the wind speed of the measured point.

Anemometer: It is a speed measuring instrument that converts the flow rate signal into an electrical signal, when the temperature changes, the resistance changes, so the voltage at both ends changes, and the flow rate is measured.

There are a total of 18 wind levels.

Wind Levels and Symbols Name Wind Speed (m per second) Land Objects Sea Surface Waves Wave Height (m) Level 0 Called No Wind m Seconds Smoke Straight Up Calm m.

Level 1 is called soft wind meters and seconds smoke indicates the direction of the wind microwave peak without droplets meters.

Level 2 is called a light breeze m seconds to feel windy and small crests are not broken m.

Level 3 is called the breeze meter second flag and the peak of the small wave breaks the meter.

Level 4 is called the Japanese wind m seconds to blow up dust and small waves of white foam crest meters.

5 strong winds, meters, seconds, small trees swaying, medium waves, foaming peaks, meters.

Level 6 is called a strong wind meter second in the electric stove with a sound of large waves to a droplet meter.

Level 7 is called a gale, meters, seconds, difficulty walking, breaking peaks, foaming at the peak, and forming a meter.

Level 8 is called a gale, meters, seconds, breaking the branches of the hidden land, the waves are long, and there are waves of spray meters.

Level 9 is called Gale Meters Seconds Small Damage Houses Wave Peak Rewinding Meters.

Level 10 is called a gale m sec uprooting trees and waves rolling and roaring m.

Category 11 is called a storm of meters and seconds of damage and the crest of the wave is all droplet meters.

A magnitude 12 is called a hurricane m/s that destroys huge waves of monstrous m.

Category 13 is called Typhoon Mipei-Lee seconds.

Category 14 is called a strong typhoon in meters.

Category 15 is called a strong typhoon in meters.

Category 16 became a super typhoon in meters and seconds.

17 levels of meters and seconds.

It can be judged. The logic of judging the wind speed (not the fraction) here is: after the wind cup begins to rotate, because the cup 2 rotates along the direction of the wind, the pressure of the wind is relatively reduced, and the cup 3 rotates at the same speed against the wind, the wind pressure is relatively increased, and the wind pressure difference is constantly decreasing, after a period of time (when the wind speed does not change and tremble), when the partial pressure difference acting on the three wind cups is zero, the wind cup becomes a uniform rotation.

In this way, the magnitude of the wind speed can be determined according to the rotational speed of the wind belt cup (the number of revolutions per second).

Features of the wind speed cup making experiment:

When the wind blows from the left, the wind cup 1 is parallel to the wind direction, and the pressure of the wind on the wind cup 1 is approximately zero in the direction of the direction straightest to the axis of the wind cup. The wind cup 2 and 3 intersect at an angle of 60 degrees with the wind direction, and for the wind cup 2, its concave surface is rotten against the wind tunnel and bears the greatest wind pressure.

The convex surface of the wind cup 3 is windward, and the wind pressure that the wind cup 2 is subjected to by the turbulent effect of the wind is smaller than that of the wind cup 2, because the pressure difference between the wind cup 2 and the wind cup 3 in the direction perpendicular to the axis of the wind cup, the wind cup begins to rotate in the clockwise direction, the greater the wind speed, the greater the initial pressure difference, the greater the acceleration generated, and the faster the wind cup rotates.

Wind speed is one of the physical quantities that describe wind, which refers to the pure volume of air flowing through a fixed point per unit time. It is usually expressed in meters per second (m s) or kilometers per hour (km h). Wind speed is an important parameter in meteorology, and it has important applications in meteorological forecasting, aviation, navigation, architectural design and other fields.

Wind speed can be queried through the meteorological data platform.

In terms of meteorological forecasting, wind speed is one of the important parameters for forecasting the weather at the forecasting station. The magnitude and change of wind speed can affect the change of weather, for example, the increase of wind speed will exacerbate the change in temperature, affect the form of precipitation, etc.

In aviation and navigation, the magnitude and direction of wind speed have an important impact on the flight or navigation of aircraft and ships. The pilot or captain needs to adjust the course and flight speed according to the wind speed and direction to ensure safety and efficiency.

Wind speed is also an important parameter when it comes to building design. Designers need to consider the impact of wind speed on the building, such as the magnitude and direction of the wind speed will affect the stability and ventilation effect of the building. Therefore, in the design of the building, the magnitude and direction of the wind speed need to be considered to ensure the safety and comfort of the building.

Surface wind speed:Refers to the wind speed of about 10 meters above the ground.

Wind direction:Refers to the direction of the wind, which is 0° in the direction of due north and positive clockwise.