Measurement of wall friction is similar to the measurement of shear stresses.
To measure the static friction, several repeating shear steps are required until the static friction reaches a maximum. The dynamic friction value follows the static friction peak. The friction is measured beginning with the lowest pressure and increasing for further steps.
It is important to simulate the roughness of the surface of the plate, because an incorrect roughness can lead large mistakes, such as the collapse of silos.
The test palette for measurement can be round or hexagonal.