A second-generation sensor has been developed to measure forces in a mechanical wood-pulp refiner. The sensor replaces a section of a refiner plate bar and is sensitive to the normal and shear forces associated with bar passing events. The active elements in the sensor are piezoelectric ceramic.

This second generation prototype is intended for use in a pressurized pilot-scale refiner in which temperatures and pressures will be as high as 160° C and 516 kPa (gauge). The frequency of force events in the pilot scale refiner is also large, with frequencies of up to 40 kHz excited by bar passing events.

The sensor is developed through application of practical engineering design strategies and the use of parametric 3D modeling to validate potential design geometries. The sensor is manufactured, assembled and bench tested to evaluate its characteristics, then implemented in lab scale refiner trials.