FBA-23
![FBA-23](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/fba23_lowres.jpg?itok=O0PM0NFD)
Detailed Description
The Force Balance Accelerometer measure the acceleration of the ground as it is shaking during an earthquake. It uses a feedback system in which the output signal from the transducer is amplified and fed back to a device that moves the mass to the original unperturbed position.
Sources/Usage
Public Domain.