Random vibration testing system

Claim 1

A VIBRATION TESTING SYSTEM COMPRISING IN COMBINATION: A SHAKER, MEANS ON SAID SHAKER TO WHICH A TEST SPECIMEN CAN BE MOUNTED FOR VIBRATION, ENERGIZING MEANS FOR SAID SHAKER CONSTRUCTED AND ARRANGED SO AS TO PERMIT AN ADJUSTMENT OF THE OVERALL FREQUENCY RESPONSE OF A SIGNAL APPLIED THERETO AND THE FREQUENCY RESPONSE OF THE APPLIED SIGNAL IN EACH OF A PLURALITY OF FREQUENCY BANDS, AN ACCELEROMETER MOUNTED SO AS TO PROVIDE A SIGNAL CORRESPONDING TO THE ACCELERATION PRODUCED BY SAID SHAKER, AMPLIFICATION MEANS CONNECTED TO SAID ACCELEROMETER, A VISUAL READING SONIC ANALYZER TO WHICH THE OUTPUT OF SAID AMPLIFICATION MEANS IS FED, MEANS FOR PERIODICALLY SWEEPING SAID SONIC ANALYZER THROUGH A BAND OF SONIC FREQUENCIES AT A RATE SUFFICIENT TO PROVIDE A CONTINUOUS VISIBLE DISPLAY THEREON, A SIGNAL SOURCE HAVING A PREDETERMINED POWER SPECTRAL DENSITY, AND MEANS FOR SELECTIVELY APPLYING THE OUTPUT OF SAID MEANS FOR SWEEPING AND THE OUTPUT OF SAID SIGNAL SOURCE TO SAID ENERGIZATION MEANS.