Probe design for high-precision eddy-current displacement sensors

Johan G. Vogel, Vikram Chaturvedi, Stoyan Nihtianov

Research output: Chapter in Book/Conference proceedings/Edited volumeConference contributionScientificpeer-review

4 Citations (Scopus)


State-of-the-art industrial Eddy-Current Displacement Sensors (ECDSs) are typically not suitable for use in high-precision applications due to their low resolution and poor stability. By using a smaller, flat sensing coil, a reference coil, a dedicated readout chip and by operating at much higher excitation frequency a higher measurement sensitivity and better mechanical and thermal stability can be achieved. To use the sensor in industrial applications, the chip and the coils must be integrated in a small package. This paper presents a probe design for a high-precision ECDS, aiming at compactness and low thermal sensitivity. In this design, the sensing coil and the reference coil are closely spaced to minimise thermal gradients. The coils can, together with intermediate shielding and capacitive tilt electrodes, be integrated into a single stack only 2 mm thick and 12 mm in diameter, which can be realised on a multilayer PCB. Thermomechanical modelling shows that placing the readout chip on a separate PCB leads to significantly decreased self-heating compared to placement directly on the stack. Experiments show that the inductance behaviour of the realised stack is similar to that of the model.

Original languageEnglish
Title of host publicationProceedings
Subtitle of host publicationIECON 2018 - 44th Annual Conference of the IEEE Industrial Electronics Society
EditorsM. Manic
PublisherInstitute of Electrical and Electronics Engineers (IEEE)
Number of pages7
ISBN (Electronic)978-150906684-1
Publication statusPublished - 2018
Event44th Annual Conference of the IEEE Industrial Electronics Society, IECON 2018 - Washington, United States
Duration: 20 Oct 201823 Oct 2018


Conference44th Annual Conference of the IEEE Industrial Electronics Society, IECON 2018
Country/TerritoryUnited States


  • Coil inductance
  • Displacement measurement
  • Eddy-current sensor
  • Probe design
  • Self-heating


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