Basics of Coordinate Metrology
Unit 7: Structure of Coordinate Measuring Machines - Stylus System

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In a measuring stylus system, the stylus is connected to a machine axis via three parallelograms perpendicular to each other. The three parallelograms enable the precise determination of the spatial deflection of the stylus in Cartesian coordinate form. The deflection from the zero position is converted into a signal. Upon being shifted from the zero position, the measuring axis positions are read.
   
There are two alternative methods of recording the value to be measured:
  • static measured value acquisition
    • The drives in the coordinate axes are tracked in such a way that the deflection of the stylus tip becomes zero or a defined measuring force is reached. The measuring point is then recorded statically, after the natural vibration of the measuring machine has subsided.
    • This probing methods gives measuring results with the lowest measuring uncertainty.
  • dynamic measuring data acquisition
    • The measuring data acquisition takes place dynamically while the probe is being deflected.
    • The deflection value of the stylus tip is added to the current values of the length measuring system.
    • In dynamic probing, a higher measuring speed can be achieved, but the measuring uncertainty is in most cases higher.

Comparison: Triggering stylus system - Measuring stylus system