Contact Electronic Gauging
Contact electronic gauging is performed by a mechanical contact touching the surface to be measured; the contact is connected to a transducer that transforms the mechanical displacement into an analog electric signal. The latter is then processed by an electronic unit, which amplifies, digitalizes and processes the signals coming from all the transducers, combines them and finally supplies the desired measurements, together with the statistical analyses, if required, and the compensation to the machine tools, as needed in certain cases.
Marposs always uses high-precision mechanical systems for the measuring chains, so as to eliminate mechanical slack or friction that might impair the quality of the measurement.
Marposs measuring cells use three basic transduction systems:
- Air Gap: this is an inductive-type system that transforms the mechanical displacemnet of a mobile ferromagnetic part with respect to a fixed coil into an inductance variation.
- LVDT (Linear Variable Differential Transformer): this is a transformer that supplies an output voltage that depends on the variation in the mutual induction between the primary circuit and the secondary one, due to the shift of a ferromagnetic core within the primary and secondary coils.
- HBT (Half Bridge Transducer): this is a Wheatstone half bridge in which the shift of a core causes an unbalance between two inductive impedances.