Digital servo accelerometer in four ranges from ±0.1 to ±1.0 g

September 28, 2012 // By Julien Happich
The Sensorex SX41800 series of high-performance digital RS-485 (MODBUS) servo accelerometers from Meggitt Sensing Systems is designed to deliver a high-reliability output, proportional to acceleration, in support of linear acceleration and deceleration measurements.

Designed for use within automatic rail and light rapid transit system monitoring and positioning control (ATO, ATP, and ERTMS), low-frequency (seismic) vibration measurement and structural monitoring applications, the accelerometers are offered in four ranges from ±0.1 to ±1.0 g. The Sensorex SX41800 digital servo accelerometer series incorporates an inertial mass mounted onto a coil, which tends to move with respect to the housing of the accelerometer when the accelerometer is subjected to motion. Based on the galvanometric principle, movement of the coil is detected optically and transduced into an electrical signal, which then excites the coil to return the inertial mass back to its null position. The amount of excitation current required to maintain the inertial mass in its null position is in direct proportion to the applied acceleration or deceleration and is therefore the output signal source. In addition, because the damped inertial servo mechanism is fully oil immersed, SX41800 series accelerometers exhibit high shock and vibration resistance with a good damping factor.

The incorporation of an inertial mass with servo feedback, together with optical position pick-up and friction-free mounting, give the Sensorex SX41800 outstanding accuracy, long-term stability and high-reliability across many demanding applications. The RS485 main output signal allows communication to a standard PC, along with user-controllable parameters of data acquisition. An analogue ±5V output signal is also available via one of the output pins. An integrated auto-test function allows the user to check the servo loop and most other associated functions. Sensorex SX41800 units are also CE EN 50155 railway norm & CE EN 61326 norm qualified.

Visit Meggitt Sensing Systems at