Unholtz Dickie Corp
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Seismic Test Systems

Long Stroke Thrusters - Seismic Test Systems

Unholtz-Dickie offers the world’s first all air-cooled, electrodynamic long-stroke testers for telecommunications, earthquake simulation, and transportation applications. Up to 2,300 lbs (1,040 kg) of payload can be supported on a 48x48 inch (1.2 x 1.2 m) footprint on either the slip plate of the horizontal LS12H thruster or the bearing-guided head expander of the vertical LS12V unit. Both are driven by the highly reliable SAI120 IGBT amplifier with an integrated switching cabinet for either vertical or horizontal testing. And because it’s an electrodynamic shaker, relatively high frequencies of up to 1,000 Hz can be achieved.


The system performs the vibration tests as specified in Telcordia’s GR-63-CORE for all three orthogonal axis

  • Sine Survey: determines the natural frequencies of communications equipment by sweeping 1 to 50 Hz at 0.2 g and 1.0 octave per minute rate.
  • Seismic Test: reproduces VERTEQII Zone 4 earthquake time waveform pulse requiring 10 inches (254 mm) of stroke at 40 inches per second (1 m/s) velocity, and 1.65 g max
  • Office Vibration: 1.0 g sweep from 5 to 100 Hz and back to 5 Hz using 0.25 octave per minute rate.
  • Transportation Vibration: 0.78 grms random from 5 to 200 Hz for 30 minutes


  • Seismic Test Force: 5,000 lbf (22 kN) pk
  • Sine/Random Force: 1,500 lbf (6.7 kN) pk/rms up to 1,000 Hz.
  • Shock Force: 7,000 lbf (31 kN) pk
  • 12 inches (305 mm) bumper-to-bumper
  • Supports up to 2,300 lbs (1040 kg) on top of a 48x48 inch (1.2x1.2 m) head expander