Electrothermal Analytical Response Inspection of Electroexplosive Devices

Abstract

Abstract : A commercial electrothermal tester and digital equipment were used to test SCD 10383 fuses and PA506 and M100 detonators nondestructively. Dissection and examination revealed positive faults on all types of devices tested (one each). Correlation was found between various NDT measured thermal parameters and sensitivity, burnout for fuses and fire/no fire results for detonators. The digital system that was developed represents a possible transition to on-line NDT of electroexplosive devices. The system could be set to accept or reject devices based on departure from present limits. The main limitation on the detonator testing was created by a small coefficient of thermal resistance of the bridge wire material which resulted in a poor signal-to-noise ratio. The system, if refined and used in production, would eliminate devices that are deficient in the bridge wire area. Comparisons with a collective thermal model indicate it would further permit culling sensitive or insensitive devices.