Support of Conventional Measuring Technique

Generally tomographic measurements can be carried out only for a few column experiments, because they are time consmning and costly. In this case the results should be used for a better interpretation of the residence time distribution measured with the conventional measuring technique and to make a statement about the exactness of the used hydrodynamic model. 

For these reasons the conventional measurements of the residence time distribution should be realized very exactly. An important influence on the information content of the tracer output function has the shape of the input function. Between the transmission function of the object co) (Fomier transform of the hydrodynamic model) and the power spectrum of the tracer input function C, ( ) and the power spectrum of the tracer output concentration distribution Co X ) the following relation exists for linear models  

Power spectra are the Fomier transform of the tracer concentration function C t) 

If the limit of frequency in the input function (o) ) is low, than the output function Cout (o) contains no information about (m) in the range co /. 

The stochastic input eft)) and output functions Cy t)) of the tracer concentration are evaluated with the correlation theorie (Lee, 1964 Solodnikov, 1971). 

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