1222 THE BELL SYSTEM TECHNICAL JOURNAL, SEPTEMBER 1953 



Fig. 10 — One of the early devices employed for shock testing of tubes under 

 controlled conditions — the MIL-E-IB bump tester. 



with the table anvil while the higher frequencies are due to table reso- 

 nances which are excited by the metal-to-metal impact of spring and 

 anvil. 



High Impact Machine for Electronic Devices 



This machine was originally intended to test the resistance of tubes to 

 high peak-short duration shocks similar in nature to those encountered 

 by equipment fastened to parts of ships that are likely to be exposed to 

 direct explosion pressures.^^ The shock is produced by a steel hammer 

 pendulum striking a movable steel table on which the tube under test is 

 mounted. The shock magnitude is given by the angle through which the 



