AIAA 95-2702, Proceedings of 31st Joint Propulsion Conference, San Diego, CA, July 1995.
Barry T. Neyer, Member AIAA
EG&G Star City, Inc.
Miamisburg, OH 45343-0529
Barry T. Neyer
1100 Vanguard Blvd
Miamisburg, OH 45342
(937) 865-5170 (Fax)
The standard test procedure for determining the output of detonators is the dent block test. A detonator is placed against a metallic block of known hardness and fired. The depth of the dent produced is used as a measure of the strength of the detonator. The dent depth is a function of the integrated pressure pulse of the detonator.
In many applications, a detonator is used to detonate a next stage explosive assembly. Often times the detonation of the next assembly is governed, not by the time integral of a pressure pulse, but by the instantaneous shock pulse. A typical example of such an "instantaneous" detonator is a device that throws a flying plate. Thus, a dent block test may not adequately characterize the performance of these types of detonators.
The Velocity Interferometer System for Any Reflector (VISAR) is a diagnostic technique that is capable of measuring the velocity of a flying plate. In addition, it is also capable of measuring the instantaneous pressure pulse produced by a detonator affixed to a (transparent) witness plate.
This paper will show that the dent block test and VISAR test measure different characteristics of the output of detonators. Moreover, the output measured by a VISAR in many cases may be a more meaningful measure of the performance of the detonator than that provided by a dent test.