Profile: Refraction Technology, Inc. specializes in offering seismic recorders, motion recorders and sensors. Both seismic & strong motion recorders provide a flexible approach to collecting seismic data for monitoring earthquakes and microseismic events in local, regional & global studies. The 130B is a customized version of the 130 broadband seismic recorder. The 130B is available in 3-channel configuration only, programmed with unity gain and has a different internal oscillator than in the 130-01 recorder. The 151-120 broadband seismometer is a force-balance feedback sensor with frequency bandwidth 0.0083 Hz (120 sec) - 50Hz flat to velocity. This 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.