High Performance Broadband Seismometer

The 151B Observer is a force-balance feedback sensor with available frequency bandwidth from 0.0083 (or 120 s) – 50 Hz.

It is ideal for use in seismicity studies due to its low self-noise performance. It can be effectively installed in observatory, portable, surface and posthole applications. Features one vertical and two horizontal, completely independent sensors with built-electronic feedback circuit.

The 151B Observer contains three independent sensors (one vertical and two horizontal) with built-in electronic feedback circuit, control and power conversion circuits, featuring low noise, large dynamic range and easy installation and use.

The 151B Observer has a built-in mass zero-position adjusting mechanism to perform automatic mass adjustment. As soon as the seismometer is powered it checks the zero position of each component’s mass and automatically adjusts the zero position if needed. Monitoring and adjustment of the mass can also be performed via the 130S series High Resolution Recorders using the Sensor Control Board.

The 151B Observer is an exceptionally low noise seismometer. The low self noise performance makes the 151B an ideal seismometer for local, regional and global seismicity studies in different installation configurations.