The patented Werth Fiber Probe (WFP) tactile sensor has been used to measure micro structures and precision components in a wide range of industrial fields for over 10 years. Typical applications include gages, spinning nozzles, miniature gears, and components for fuel injectors. Due to its low contact force and physical principle, the WFP is also suitable for calibrating optical measurements. With several hundred installations worldwide, the Werth Fiber Probe is currently the most commonly used microprobe. It was developed in a joint effort with the German National Metrology Institute (Physikalisch Technische Bundesanstalt – PTB).
The fiber probe continues to be developed under the same arrangement. In one variant of the fiber probe, for example, a laser diode is used as the light source. It generates a speckle pattern that can be used to determine the three-dimensional position of the contact sphere. Low probing uncertainties can be achieved by directly evaluating the contact element. Resolution is in the nano range, and is ultimately dependent only on the optics used. One advantage of the WFP, for example, is that direct measurement of the contact element means that bending of the probe shank has no influence on the measurement result. The probe shank is also continuously kept in motion by a vibration generator (patent pending), in order to prevent stick-slip effects.