What is the measuring principle of capacitive displacement sensor?

A capacitive displacement sensor is a non-contact sensor used to measure the change in displacement, position and thickness measurement of an object by detecting variations in capacitance.


The principle of capacitive displacement sensor is based on the formation of an electric field between two electric plates, with a dielectric material between them. If a constant alternating current flows through the sensor capacitor, the amplitude of the alternating voltage on the sensor is proportional to the distance between the capacitor electrodes. The alternating current is demodulated and output as an analog signal.

The use of capacitive sensors

These sensors are widely utilized in various industries, such as automotive, aerospace, manufacturing and research, due to their high precision, sensitivity and reliability.


The sensors measure against all electrically conductive materials and with appropriate electronic circuitry even against insulators. 
Capacitive sensors work in clean environments.

Benefits of the measuring principle

  •  Wear-free and non-contact measurement 
  •  Distance and thickness measurements on conductive and non-conductive objects
  •  Unmatched accuracy and stability
  •  High bandwidth for fast measurements
  •  Ideal for industrial environments, magnetic fields and vacuum

Unmatched precision

Practice shows that capaNCDT measuring systems achieve excellent results in terms of linearity, repeatability and resolution. While sub-micrometer precision is reached in industrial environments, high-precision sub-nanometer measurements are carried out in clean environments.

Modern and user-friendly controller technology

Modern capaNCDT controllers are the ideal basis for different fields of applications. Various interfaces and ease of use via web interface allow for a fast integration into the respective application environment.





  •  Active guard ring electrode
  •  Fast sensor replacement without calibration
  •  Largest product range worldwide (flat sensors, sensors with integrated cable, sensors with thread…)
  •  Extremely high stability
  •  Measuring ranges   0.05 to 10 mm
  •  Resolution 0.04 nm
  •  Temperature stability 11 ppm/°C

Capacitive thread sensors for demanding installation scenarios

capaNCDT sensor

     Measuring ranges 0.5 / 1.25 / 2 / 3mm
     Socket connection
     Mounting via internal thread or screw nut

Compact & capacitive single-channel system

capaNCDT 6110

     Measuring ranges  0.05 -10 mm

     Linearity   0.2 %

     Resolution   0.01 %

     Frequency response  up to 20 kHz (-3 dB)


Modular multi-channel system for highest precision

capaNCDT 6220

     Measuring ranges  0.05 -10 mm

     Resolution   0.0005 %

     Frequency response  up to 20 kHz (-3 dB)

     Digital data rate  4 x 3.9 kSa/s


Capacitive multi-channel system for highest resolution

capaNCDT 6500

     Measuring ranges  0.05 -10 mm

     Linearity   0.05 %

     Resolution   0.000075 %

     Frequency response  8.5 kHz (-3 dB)

     Temp. stab.  9 ppm/°C (controller)

Active capacitive measuring system for long signal transmission paths

capaNCDT 61x4

     Measuring ranges  2 mm

     Linearity   max. 2um

     Resolution   max. 0.3um

Capacitive measuring system for industrial applications

capaNCDT 61x0/IP

     Measuring ranges   0.5 | 1 | 1.25 | 2 | 3 | 4 | 6

     Linearity   max. 1 µm

     Resolution  max. 0.05 µm

For precise thickness measurements of plastics


     One-side thickness measurement of plastic films and coated metals
     Target thickness: 40 μm to max. 6 mm
     Integrated temperature measurement for output of sensor temperature
     Temperature range (sensor) -10 °C … +85 °C
     Integrated function to determine the permittivity

Measuring the Disc Thickness Variation (DTV)


     Multi-track thickness measurements
     Comprehensive software with real-time evaluation
     Dynamic measurements up to 20 kHz
     For test benches, road tests and quality assurance

Robust measuring system for mobile gap measurement

capaNCDT TMD6-22

     High accuracy & intuitive operation
     Preset measurement modes for immediate operational readiness
     Comprehensive sensor portfolio
     Ideal for mobile applications in service and maintenance tasks


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