Listing ID #3172894
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Contact SupplierA Wind vane is used for indicating the direction from which the wind is blowing. A Wind vane consists of a horizontal Arm carrying a rectangular flat fin mounted by means of thrust rod and brass bushes in a support. The horizontal arm is balanced about its axis of rotation by counter weight attached to the end opposite to the fin. The vane and eight direction rods are supported on a suitable galvanized iron pipe threaded into a base. Casting Four direction arms carry the letter N, E, S & W which point towards the corresponding true direction while four direction rods indicate the intermediate directions. The position of the counter weight with respect to the eight direction arms indicate the wind direction and may easily be determined by interpolation to the nearest sixteen points of the compass.
Details :
General Description :
Surface wind is best measured by a wind vane and anemometer. Wind direction should be reported to the nearest ten degrees. Wind direction is defined as the direction from which the wind blows and is measured clockwise from geographical north. The windvane consists of a metal sheet of rectangular form fastened to a metal rod, pivoted and capable of rotating around a vertical axis with a minimum of friction. The weight of the metal sheet is balanced by a metal counter weight at the other end of the rod.
For the purpose of obtaining a satisfactory measurement, a windvane will be suitable if it is well balanced so as not to have a preferred position in case the axis is not vertical and if it is sufficiently well designed to have single equilibrium position with respect to each wind direction.
Dimensions : The general arrangment and main dimensions of windvane shall be as shown in figs. 6.1. and 6.2.
Accuracy : When the complete instrument on final assembly is held firm at bottom and the balance weight imparted an impact by a hammer weighing 0.72 Kg and having a handle length of 240 mm, it shall make not less than five and not more than ten complete revolutions.
The material used for the fabrication of the wind instrument shall be such that it may withstand permanent exposure in the open and have a long life extending over a number of years. Suitable materials for the various components of the instrument are suggested below :
Material | Component |
---|---|
Aluminium | Base, mounting ring for direction arms, collar, arm support and horizontal arm. |
Aluminium alloy | Fin andl bearing housing cap |
Aluminium casting | Support tube |
Brass | Spindle and cap nut · |
Galvanissd steal | Main support and direction letter |
Mild steel | Balance weight and direction letter |
Tin bronze | Bearing brush |