The particle velocity at the entrance of the test bend was calculated by the air flow rate known (the mass flow rate was set using a choked flow nozzle downstream of a pressure regulator) and the air pressure just prior to the bend entrance measured. For each of the tests, data of blow tank air pressure, the pressures just prior to all the bend sand the mass of erodent conveyed against time (from the gain in weight in the receiving hopper) were collected, so that the conveying characteristics for the test material could be obtained. For data analysis it was assumed that the particles would approach the air velocity at the entrance of the bend, due to along acceleration distance of the erodent particles in a straight pipe of more than 20m. Previous work [12] has proved this assumption to be reason able for conditions that are well above the minimum conveying velocity of the particles (34 m/s air velocity in this case is well above the 12 m/s minimum conveying velocity for this material) which the acceleration distance requires at least 10 m or above.The mass of erodent material conveyed in each test run was recorded, and therefore the mass flow rate of solids