Non-intrusive measurement of solids mass flow in pneumatic conveying

Mass flow measurement of pneumatically conveyed solids presents a range of problems resulting in many different approaches to the measurement system. The authors review nonintrusive instruments and discuss true mass flowmeters and inferential mass flowmeters. True mass flow meters are based upon either the Coriolis or the gyroscopic principle. Several inferential systems are considered. Gamma attenuation has advantages at high operating pressures but has limited resolution and restricted speed of response. Electrical capacitance devices are widely used but field uniformity problems may introduce errors. Magnetic resonance is useful for materials which exhibit NMR properties but is relatively expensive.