2.1 Wind Speed
- cup
anemometer
- vane
oriented
- propeler
anemometer
- transducers
Although
wind is a vector quantity and may be measured and processed as such, it is common to measure and/or process the scalar
components of the wind vector separately; i.e., wind speed (the magnitude
of the wind vector) and wind direction (the orientation of the wind
vector). Wind speed determines the amount of initial dilution experienced
by a plume, and appears in the denominator of the steady-state Gaussian
dispersion equation (in the non-steady-state puff model, the wind speed
determines the plume/puff transport). In addition, wind speed is used in:
-
the calculation of plume rise associated with point source releases,
-
to
estimate aerodynamic effects in downwash calculations,
-
in conjunction
with other variables, in the determination of atmospheric stability
(Section 6.4.4).
Instruments used for in situ monitoring of wind speed are
of two types: those which employ mechanical sensors (e.g., cup and
propeller anenometers) and those which employ non-mechanical sensors (hot
wire anenometers and sonic anenometers). The non-mechanical sensors are
beyond the scope of this guidance and are not addressed in the following;
however, this should not preclude their use. When these types of
instruments are to be used in support of regulatory actions, prior
approval should be obtained from the reviewing authority as to
how the data will be collected, processed, and quality assurred.
Guidance
on the use of remote sensing platforms for measuring wind speed is
provided in Section 9.
2. PRIMARY METEOROLOGICAL VARIABLES
2.1 Wind Speed
2.1.1 Cup Anemometers
2.1.2 Vane-oriented and Fixed-mount Propeller Anemometers
2.1.3 Wind Speed Transducers
2.2 Wind Direction
2.2.1 Wind Vanes
2.2.2 U-V and UVW Systems
2.2.3 Wind Direction Transducers
2.2.4 Standard Deviation and Turbulence
Data
2.3 Temperature and Temperature Difference
2.3.1 Classes of Temperature Sensors
2.3.2 Response Characteristics
2.3.3 Temperature Difference
2.3.4 Sources of Error
2.4 Humidity
2.4.1 Humidity Variables
2.4.2 Types of Instrumentation
2.5 Precipitation
2.6 Pressure
2.7 Radiation
2.8 Recommendations
