The strong motion sensors are part of a complete system, Model SSA-2, produced by Kinemetrics. The recorder is a solid state unit having 2 megs of event(s) memory storage giving it a recording capacity of 3 channels for 10 minutes at 200 samples per second. The system uses three Model FBA-23 force balanced accelerometers capable of handling +/- 2g. The system can be controlled and interrogated remotely via a modem or directly by a computer. It is powered from AC but has an onboard backup battery which will last for several days in the event of a power failure. The entire unit is housed in a water-tight cast aluminum box with the three remote sensors also enclosed in water tight metal enclosures.
The sensors are triaxially mounted on a metal plate that is bolted to the concrete floor in my garage at location 37.728895N Latitude X 122.411583W Longitude. A similar unit is normally installed in my hangar at the Oakland Airport, but has been temporarily removed for use with my field equipment later this summer.
Larry Cochrane - www.seismicnet.com/contact.html