The main drawback of IR thermography is the fact that the result is influenced by a number of factors such as the thermo-optical properties of the object ( emissivity, transmissivity, reflectivity ), ambient temperature, environment properties, etc . Especially the knowledge of the measured object optical properties are fundamental for an accurate temperature measurement.
22.
Where " s " is the transmissivity and storativity of the aquifer around the well ( m?/ s and unitless, respectively ), " r " is the distance from the pumping well to the point where the drawdown was observed ( m ), " t " is the time since pumping began ( seconds ), and " W ( u ) " is the " Well function " ( called the exponential integral, E 1, in non-hydrogeology literature ).
