Abstract:
Concepts presented herein relate to a portable device (10) that includes a frame (20) and a fixture (22) for engaging a mechanical probe (12) to be calibrated. The fixture (22) can be a platform of hard material that receives pushing action of the mechanical probe (12). A displacement sensor (30) senses position of the platform (22) with respect to the frame (20). An actuator is coupled to the displacement sensor and a controller (32) is coupled to the actuator. The controller (32) operates the actuator to cause the platform (22) to move to a position (as indicated by the displacement sensor (30)), while the force required to cause the displacement is measured with a force sensor.
Abstract:
A method of determining onset of a significant event, such as point of engagement, in experimental data (302, 402) such as data measured during indenter (100) or tensile/compression tests. The measured data (302, 402) is processed by differentiation (412, 518) and/or integration (414, 522) to generate a plurality of processed series (413, 415, 417, 512, 524, 532). The method includes setting an upper bound (806, 906) and a lower bound (808, 908) based on thresholds selected as multiples (424, 530) of a standard deviation (421, 528). The significant event (602, 810) is determined from one or both of the upper and lower bounds (806, 906, 808, 908). The method can include calculating an uncertainty (308, 408, 542) for the significant event determination (602, 810).