The ease of manipulation and relatively low cost of quality control-oriented viscometers have made easy the access to concentric cylinder viscometers. However, there is not widely accepted criterion to define how to define the sequence ramp time in the rheology measurement process. To this purpose, an experimental study has been made on 62.5% w/w copper concentrate to assess the effects of both flow inertia and particle settling. It has been found the existence of a 'good' combination of ramp time and acceleration reflecting a compromise between both effects. A plot between ramp time and viscosity reveals a monotonically decreasing relation.