The use of random vibration as a screen for latent
workmanship defects found in electronic equipment has proven to be more
effective than the sinusoidal form of excitation normally employed. The major
deterrent to universal acceptance of this technique is the impact this type of
test would have on program costs since a random vibration test facility is
A concept for economically generating random vibration was evolved and has
been developed which capitalizes on the fact that most major electronic
equipment manufacturers maintain basic electrodynamic sinusoidal vibration
test facilities. This technique, which was structured to utilize these
existing facilities, employs a cassette tape deck, in lieu of expensive random
programming devices, to excite the basic shaker system.
This method of random vibration generation is accomplished as
a. The system transfer characteristics to a 1.09 (peak) sine sweep input
(i.e., Power Amplifier Input versus Peak
Acceleration) are recorded (Figure 1-1).