3.9. Hydrocyclones enhanced by monitoring and automatic controlAlthough the hydrocyclone has a number of merits, its separation performance is never perfect and numerous efforts are still continuing along different directions for achieving optimum solutions. Accordingly, non-invasive and quick monitoring of hydrocyclone per- formance are important for enhancing the separation performance of hydrocyclones. It has been acknowledged that the spray angle can be employed as an indicator for monitoring the separation performance of hydrocyclones. Hence, in order to assess the separation perfor- mance of hydrocyclones, Gutierrez et al. utilized electrical im- pedance tomography (EIT) to control hydrocyclone underflow dis- charge. Petersen et al. and Van Vuuren et al. used image processing techniques to measure spray angle and spray width, re- spectively. Rashid et al. linked the spray angle in pressure swirl atomizers with design and operating variables by applying “Image J software”. Mazumdar et al. attempted to apply an image pro- cessing based algorithm on MATLAB to quantify the spray angle of hydrocyclones at different various operating conditions. Aldrich et al. employed multivariate image analysis to estimate the particle size in underflow of hydrocyclones.Furthermore, to verse the amendment of operating state of hydrocyclones with corresponding change in underflow discharge pat- tern. Dubey et al. captured and analyzed the underflow discharge profile by utilizing a digital camera and an image processing algorithm, respectively. Results verified that the spray angle was sensitive to the variations of design and operating variables.