An on-line powder pressure-displacement measurement system was developed based on a static measurement instrument ( vernier caliper). This system consists of a pressure sensor and a displacement subsystem, and has the on-line capability to measure the thickness of powder packing with different powder sizes. The design principle employs a pressure sensor to determine the thickness by different signals generated when the pressure sensor contacts the free surface zone of powder packing and when it contacts the other powder zone. The powder materials adopted to validate this newly developed system were glass beads, sand and dust. This measurement technique can be applied under different measurement conditions. (c) Koninklijke Brill NV, Leiden and Society of Powder Technology, Japan, 2008