Analysis of silt in rivers and canal systems is of basic importance. Design of channels and their subsequent maintenance mainly depends upon the type of sediment expected to flow during their operation. Uppal Air Siltometer was developed using air far silt anaylsis and was published in “La Houille Blanche” Grenoble, France, Vol. 6, November-December 1951. It gave the sizi distribution curve directly and was quick as compared to other siltometers. Some modifications have been carried out to make the analysis automatic and to improve the constancy and reproducibility of the instrument which has been described in this paper.
