Engdahl Enterprises has announced their new Peak Shock Recorder Model 1200 that senses and records the shock spectrum caused by earthquakes, storms, and explosions. The recorder is useful whenever acceleration measurements are desired at low frequencies. The plot of the recorder's twelve individual measurements is the shock spectrum of the acceleration to which the recorder was subjected.
The PSR 1200 is a twelve-channel direct-recording accelerometer, which effectively plots a frequency spectrum of the applied shock and is completely self-contained. Twelve reeds of different lengths and weights, one for each frequency, are fabricated from spring steel. A diamond- tripped stylus is attached to the free end of each reed to inscribe a permanent record of its deflection on one of twelve record plates. A calibration sheet for each recorder lists the resonant frequency and sensitivity of each reed. The Peak Shock Recorder can be used in connection with dams, high-rise structures, nuclear power plants, mines, ships, earth studies, and oil explorations.