Folks I have gone through the journal paper titled "Turbulent and transitional velocity measurements in a rectangular microchannel using microscopic particle image velocimetry" Experimental Thermal and Fluid Science 29 (2005) 435446. In this paper the authors have mentioned the maximum flow rates through the microchannel was 60 ml/min. So I just want to know at such a high flow rate how the raw micro PIV images (prior to processing for velocity field through any correlation techniques) does look ? Is in the above raw PIV images the seeding particles are clearly visible? I was able to get raw PIV images for very low flow rates where the seeding particles were clearly visible as dots in the images. -- With Best regards & Wishes Mohammed Asfer Phd(ME, Microfluidics and sensors Lab Hall-8,G-217 IIT Kanpur UP INDIA ,208016 Ph No (0)9889614690 asfer786@gmail.com *************************************************************** To find what you seek in the road of life, the best proverb of all is that which says: "Leave no stone unturned." Edward Bulwer Lytton ***************************************************************