Abstract
Recently, an accelerometer-based device (Vienna Surface Tester (VST)) has been developed for testing the surface characteristics of floors, beddings and turf grounds. The accelerometers are placed in a sphere, which will be dropped in free fall on a test surface. By observing changes in acceleration during impact, researchers can deduce various material characteristics. A down-sized version of this device (Surface Tester of Food Resilience (STFR)) has been proposed for texture testing of foods. Whereas the movement of the VST can be described by the laws of free fall, the STFR follows a constrained circular path due to its attachment to a rod and swivel. We refined the mathematical representation of the different phases of the STFR spherical probe's trajectory (fall, impact and rebound), and we modified the mathematical models for the STFR probe to extend the measurement range.