The feasibility of detecting corrosion in electric fuzes using the thermal transient technique

The object of this experiment was to determine if the thermal transient test can be used to detect corrosion on the bridgewire in an electric fuze or electroexplosive device (EED). The fuzes are used to set self-destruct times in the following mines: M74, M75, BLU-92/B. When the mines are exposed to high humidity the bridgewire inside the fuze is susceptible to corrosion. An open (corroded) fuze may initiate the wrong self-destruct time which in turn will create a hazardous condition for friendly troops. Two examples of severe corrosion of the bridgewire in a fuze are shown. These photographs were taken by a scanning electron microscope. The current method for detecting corrosion in a fuze is measuring the cold resistance of the bridgewire. A high resistance reading indicates evidence of corrosion. It will be determined if the thermal transient test can be used as an alternative method. The thermal transient test is a nondestructive examination technique for inspection of the critical bridgewire interface. The test allows one to see inside the fuze non-destructively and determine if certain failure conditions or abnormalities are present.