Non-contacting displacement sensors

Picture of a non-contacting displacement sensor

In many monitoring applications non-contacting eddy current displacement sensor (ECDS) systems are the preferred sensor choice for a wide range of monitoring tasks. They are typically used for measurement of relative shaft vibration and displacement, as well as for use as reference sensors. Our ECDS systems can be divided into the following groups:

Non-contacting ECDS sensors standard

SD-051

  • Measurement range 2 mm
  • 5 mm tip diameter
  • Full length thread
  • Up to 180 °C
  • Data sheet SD-051

 

SD-052 (Discontinued)

  • Measurement range 2 mm
  • 8 mm tip diameter
  • Full length thread
  • Up to 180 °C
  • Data sheet SD-052

 

SD-053 (Discontinued)

  • Measurement range 2 mm
  • 8 mm tip diameter
  • Reverse-mount design
  • Up to 180 °C
  • Data sheet SD-053

 

SD-054 (Discontinued)

  • Measurement range 2 mm
  • 8 mm tip diameter
  • Right-angled design
  • Up to 180 °C
  • Data sheet SD-054

 

OD-051/053/054/055

 

SD-081 (Discontinued)

  • Measurement range 3.5 mm
  • 8.2 mm tip diameter
  • Full length thread
  • Up to 180 °C
  • Data sheet SD-081

 

SD-083 (Discontinued)

  • Measurement range 3.5 mm
  • 8.2 mm tip diameter
  • Reverse-mount design
  • Up to 180 °C
  • Data sheet SD-083

 

SD-084 (Discontinued)

  • Measurement range 3.5 mm
  • 8.2 mm tip diameter
  • Right-angled design
  • Up to 180 °C
  • Data sheet SD-084

 

SD-087/088/089(Discontinued)

 

OD-081/083 (Discontinued)

 

SDH 151

  • Measurement range 4.0 mm
  • High temperature 
  • Full length thread
  • Cable protection
  • Up to 350 °C
  • Data sheet SDH 151

 

OD 151

 

SD-161

  • Measurement range 8.0 mm
  • 17 mm tip diameter
  • Full length thread
  • Up to 180 °C
  • Data steet SD-161

 

SD-164

  • Measurement range 8.0 mm
  • 17 mm tip diameter
  • Right-angled design
  • Up to 180 °C
  • Data steet SD-164

 

OD-162/165

 

EC-001/002/003

 

EC-045/099

IN-081

 

IN-083

 

IN-084

 

IN-085

This eddy-current displacement sensor system is part of the whole new sensor family ds820. Robust yet precise, these industrial sensors cover a measuring range of up to 4 mm. An intelligent driver unit makes them easy to set up and keep spares.

Features

  • Non-contacting eddy current displacement sensor system (ECDS system)
  • High precision
  • Series ds821 for standard applications
  • Measuring range 2 mm and 4 mm (8 mm to be released soon)
  • System cable lengths 5 m or 10 m
  • One ECDS driver unit (oscillator/demodulator) for both system cable lengths with autoselection of system cable length
  • Push-pull self-latching connectors for secure, fast and easy installation on site
  • Excellent temperature stability
  • Operating temperature range of the sensor probe from –50 °C to +180 °C
  • Operating frequency range DC to 10 kHz
  • Advanced pressure-resistant ceramic probe cap for use in harsh surroundings
  • Fulfills the requirements of API 670 and DIN ISO 10817-1

 

Applications

Suitable for a wide range of industrial machines. Typically used for measuring:

  • relative shaft vibration
  • axial shaft position
  • radial shaft position
  • eccentricity

 

Use as speed sensor and phase reference sensor

  • Measurement of speed, rotational direction and zero speed detection

Non-contacting ECDS sensors for hazardous areas

Features

  • Non-contacting eddy current displacement sensor system (ECDS system)
  • Measuring range 2 mm
  • Operating frequency range DC to 10 kHz
  • Operating temperature range for the sensor probe from –30 °C to +180 °C
  • Sensor complies with protection class IP 68 according to DIN EN 60529
  • Sealed ceramic sensor tip (up to 12 bar) perfectly suitable for ambient conditions with increased humidity
  • Design with 5 m and 10 m nominal system length available
  • Gold-plated connectors for connection integrity
  • Fulfills the requirements of API 670 and DIN ISO 10817-1
  • Approved for use in hazardous areas according to directive 94/9/EG ATEX
  • Various housing designs and lengths to allow for the correct choice according to the given mounting requirements
  • Metric or imperial thread (M10x1 or 3/8"-24UNF)

 

Applications

  • Measurement of relative shaft vibration
  • Measurement of axial shaft position
  • Measurement of radial shaft position
  • Measurement of eccentricity

 

Use as speed sensor and phase reference sensor

  • Measurement of speed, rotational direction and zero speed detection

INA-081

 

INA-083

 

INA-085

This eddy-current displacement sensor system is part of the whole new sensor family ds820. Robust yet precise, these industrial sensors cover a measuring range of up to 4 mm. An intelligent driver unit makes them easy to set up and keep spares.

Features

  • Non-contacting eddy current displacement sensor system (ECDS system)
  • High precision
  • Series ds822 approved for use in hazardous areas according to directive 94/9/EG ATEX
  • Measuring range 4 mm (2 mm and 8 mm to be released soon)
  • System cable lengths 5 m or 10 m
  • One ECDS driver unit (oscillator/demodulator) for both system cable lengths with autoselection of system cable length
  • Push-pull self-latching connectors for secure, fast and easy installation on site
  • Excellent temperature stability
  • Operating temperature range of the sensor probe from –50 °C to +180 °C
  • Operating frequency range DC to 10 kHz
  • Advanced pressure-resistant ceramic probe cap for use in harsh surroundings
  • Fulfills the requirements of API 670 and DIN ISO 10817-1

 

Applications

Suitable for a wide range of industrial machines. Typically used for measuring:

  • relative shaft vibration
  • axial shaft position
  • radial shaft position
  • eccentricity

 

Use as speed sensor and phase reference sensor

  • Measurement of speed, rotational direction and zero speed detection

With the newest ATEX supplement of the EC-Type-Examination Certificate of our eddy current displacement sensor Series ds822 it is possible to realize longer cable length for intrinsically safe installations. This is possible on account of the fact that the system’s contribution to the inductivity Li is now rated as negligibly low.

In the context of intrinsically safe ATEX installations one has to note that according to IEC 60079-14:2007 clause 12.2.5.2 the Co and Lo used in the calculation for the cable length must be only the half value if both Ci and Li are more than 1% of the  Co and Lo.

The stated Co and Lo refer to the maximum capacity and inductivity which are allowed to be connected to the energy-limiting device (safety barrier or isolating amplifier). Whereas the values Li and Ci denote the capacity and inductivity of the field equipment that is supposed to be connected to the energy-limiting device. In the present case these are the values of the driver od822 which are stated in its EC-Type-Examination Certificate. Beside the characteristics of the field equipment one has for the calculation of the maximum permissible length to take into account the capacity of the signal cable Cc and its inductivity Lc. The following relations must be fulfilled:

Co ≥ Cc+ Ci and Lo ≥ Lc+ Li

In practice requirements to the inductivity have normally no limiting character. Limiting requirements for the maximum cable length result typically from the inequality of the capacities. For a given application the values of the driver Ci and the energy-limitting device Co are known. For the capacity of the cable Cc the following requirement can be derived:

Cc ≤ Co - Ci

The device specific values for Co and Li are dependent on the given gas group of the application. For IIC gases these are normally so low that halving of the values led to a restriction of the permissible cable length to a magnitude of 100 m. With the new rating of the inductivity  Li of the driver ds822.od as „negligibly low” the precondition of halving the values of Co and Lo doesn’t exist anymore. Based on a cable capacitance of 200 pF/m according to IEC 60079-14:2007 lengths of above 400 m are possible now.

Discrete eddy current displacement sensor systems consist of:
  • The sensor probe with a certain length of integral cable
  • A electrically tuned connection cable to complete the nominal system length
  • A driver (oscillator/demodulator) containing the remaining electronics of the sensor system and which represents the interface to the succeeding monitoring system

ECDS systems with a discrete design are listed together with their respective connection cables (EC) and drivers (OD).

Eddy current displacement sensors with integrated design have a built-in driver electronic within their probe housing including all components of the tuned oscillating circuit. Therefore no separate oscillator/demodulator and calibrated connection cable is required.

To ensure complete satisfaction with the choice you make, we recommend that you discuss your application with our specialists to confirm that the appropriate design and type is selected.

Sensors are the "fingertip" in any vibration measuring system. They are the determining factor for its success.