A novel dual-material collision electrostatic probe was developed and calibrated in an ejector-funnel setup, which produced charged particulate flow with different magnitudes and polarities of charge density on the particles. The charged particles then collided with the dual-material probe tip, with the transferred charges/currents recorded by electrometers. Experiments were conducted to examine the effects of particle charge density, solid flux, particle collision velocity and angle during the charge transfer process between particles and the probe tip surfaces. A semi-empirical transferred current model which quantifies the effect of the above parameters is proposed, building on the linkage of transferred current measured by the probe and the charge density on the particles. (C) 2013 Elsevier B.V. All rights reserved.