3-Axis Digital Broadband Seismometer

Model ESDA-120S Overview

Encardio-rite model ESDA-120S is a three component low noise feedback, velocity output broadband seismometer. The Broadband Feedback seismometer is based on an orthogonal three axis low noise sensor modules with double nested feedback loop topology. The suspension system is based on the principles of “elastica”. The mechanical sensor orientation is Non-Galperin with -75 dB cross axis rejection on all axis.


  • The sensor frequency response covers the complete seismic spectrum with a flat frequency response (no peaks) from 0.008333 Hz (120 seconds) to 150 Hz.
  • The sensor noise level crosses (below) the New Low Noise Model (NLNM) from 18-20 Hz to 45-50 seconds period.
  • Truly portable rugged seismometer with fine pitched adjustable feet manufactured from phosphor bronze.
  • The sensor can be operated with ±5.0 degrees of tilt, and microprocessor-controlled remote centring is provided.
  • Remote electronic mass locks and unlock facility, with a serial interface for sensor control and parametric sensor data.
  • Galvanically two-stage isolated electronics. The sensor mechanical section and the feedback electronics sections have their own isolated and hermetically sealed enclosures.
  • The electronic and the mechanical sections of the sensor can be physically separated for observatory applications.
  • Consumes less than 1 Watt. Operates from +9VDC to +36VDC range, with input power polarity protection.
  • All outputs and digital inputs are transient protected.
3 Axis Digital Broadband Seismometer
3 Axis Digital Broadband Seismometer