AS NZS 3580.14:2014 pdf free

AS NZS 3580.14:2014 pdf free.Methods for sampling and analysis of ambient air
This Section applies to the determination of wind speed and direction for the purpose of air quality applications at wind speeds ranging from the lowest measurable with this type of equipment, i.e. less than 0.5 m/s up to gale force and above, in various terrain categories and environmental conditions at heights typically from 10 m to 100 m above ground level. This Section has been developed for use in air quality monitoring applications, however, it may be applied in other fields of study.
Wind velocity is a three-dimensional vector quantity with small-scale random fluctuations in space and time superimposed upon a larger-scale organized flow. However, for the purpose of air quality monitoring applications, surface wind is considered as a two-dimensional vector quantity specified by two numbers representing direction and speed.
The output of these sensors is typically connected to data logging systems to both convert the signal into engineering units and to record the data. These sensors are mounted at a standard height to ensure uniformity for this type of measurement.
The cup anemometer has cups that relate the rate of rotation to the wind speed. The cup anemometer’ s dynamic performance characteristics (starting threshold and distance constant) are density-dependent, but its transfer function (rate of rotation versus wind speed) is independent of density. The cup is not very efficient and creates turbulence as the air flows through and around it. The cup anemometer is omni-directional in a horizontal flow situation but exhibits a complicated reaction to vertical flow situations. It may indicate speed slightly greater than the total speed when the flow is not horizontal.
The wind vane is perhaps the simplest of instruments. A fin is fixed to a vertical shaft so that when force is applied to the area by the wind, it will turn the shaft, seeking a minimum force position. The relationship of the shape, size, and distance from the fin’s axis of rotation to the bearing assembly and transducer torque determines the starting threshold.These attributes of the fin area, along with its counterweight, determine the dynamic performance characteristics of overshoot (damping ratio) and delay distance (distance constant) of the direction vane.AS NZS 3580.14 pdf free download.