Sand content is the volume percentage of particles larger than 74 microns. Periodic determination of the sand content in a drilling fluid is desirable. Excessive sand may result in the deposition of a thick filter cake on the wall of the borehole, in turn it may settle in the hole around the tools when circulation is stopped and may cause interference with the successful operation of drilling or when the casing is set. High sand content also causes excessive abrasion of pump parts and pipe connections.