Laser sheet at grazing incidence

The first method is an optical method based on the use of a laser sheet at grazing incidence. With this method, it is possible to follow the deposit thickness and kinetics in situ and real-time. The second method is an acoustic method. The analysis of the acoustic wave of the deposit with time enables its thickness to be followed. Moreover, variations of the amplitude of the acoustic wave are linked to possible changes in the structural properties of the deposit. Nonetheless, only qualitative variations are available. The use of both methods on the same apparatus will enable a complete characterization to be obtained (Figure 11.1). 

In Situ Deposit Characterization with an Optical Method Using a Laser Sheet at Grazing Incidence... 

The first innovative method (LSGI) is based on the use of laser sheet at grazing incidence. It enables the deposit thickness at several locations in the vertical direction to be measured and the deposit thickness profile in a channel cross-section (z) to be obtained. Moreover, with this method it is possible to follow the deposit kinetics in relation to flow rate variations. First results were obtained with day suspensions and showed good reproducibility. Local measurements in conjunction with global measurements (flux or pressure) enable the deposit structure to be studied. It is now a tool that is used in our laboratory to study the suspension of... 

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