A new technique is proposed for the direct measurement of capillary forces in systems of relevance to the infiltration processing of metal matrix composites. Capable of handling melt temperatures up to 1500 K and infiltration pressures up to 20 MPa, the technique is essentially a high-temperature analogue of mercury porosimetry. Its accuracy is demonstrated by comparison with other techniques and its use is illustrated with the infiltration of diamond particle preforms by Al and Al-Si alloys at 973 K. (c) 2006 Elsevier Ltd. All rights reserved.