A method involving the internal positioning of probe capillaries to measure the recycle ratio in an internal recycle reactor equipped with a basket containing a powdered catalyst is reported. The variation of recycle ratio with carrier gas composition, pressure, temperature and catalyst mass is presented. Based on the calculated pressure drop and the principles governing flow resistance across the catalyst bed, the observed relationships between recycle ratio and experimental variables are explained. (C) 2010 Elsevier B.V. All rights reserved.