Servo-accelerometer SX41800



  • Analog output (±5V) & digital output (RS485)
  • Specially designed for severe environments (shocks, vibrations, electromagnetic perturbations)
  • Very long term stability
  • Outstanding performances
  • European Standard of Electromagnetic compatible
  • Oil damped servo mechanism
  • Auto-test function

Servo-accelerometer SX41800


The Meggitt (Sensorex) SX41800 is a high performance digital RS485 (MODBUS) servo- accelerometer designed to deliver an output proportional to an acceleration.

The incorporation of an optical infrared sensor and an inertial mass with servo feedback, as well as optical position measurement and friction-free mounting, gives the SX41800 outstanding accuracy, long term stability and high reliability.

Unit can directly interface with any standard PC, with fully user-selectable acquisition and set-up parameters. Analog voltage output is also available.

Moreover, an integrated auto-test function enables checks of servo loop and associated functions. Also, the damped servo mechanism being fully oil immersed, this device offers high resistance to shocks and vibrations.

Meggitt (Sensorex) SX41800 is also CE EN 50155 railway norm & CE EN 61326 norm qualified.

A galvanometer located within the core of this sensor is sensitive to the effects of gravity. While subjected to an acceleration, the inertial mass, mounted on a coil, tends to move with respect to the sensitive axis. This movement is then measured by an optical detector and converted into a current.

The current brings the inertial mass back to its original position. By measuring the required current for maintaining pendulum stability, the servo-accelerometer produces an output that is proportional to the applied acceleration.


  • Linear acceleration/ deceleration measurements
  • Automatic train position control (ATC, ATP, ERTMS)
  • Low frequency vibration measurements (seismic monitoring)
  • Structure and building movement monitoring
Download product data sheet Technical data sheet