Instrumentation for Measurement of Stray Energy in Electroexplosive Devices

The requirement o f making systems containing electroexplosive devices unsusceptible to electromagnetic radiation has established a need for instrumentation capable of providing more information than simple go-no-go tests with live devices and capable o f providing the information in a manner suitable for automatic data recording and evaluation. The instrumentation must meet certain requirements. Out of the many different possibilities o f making instrumentation, two methods have evolved as being most practical or best meeting the requirements, namely use of an rf detector to measure voltage across the bridgewire of an electroexplosive device, the impedance of which having previously been measured at all frequencies, and use of a thermal detector to measure heat generated in the bridgewire. Each method has its own set of advantages and disadvantages, thereby indicating that choice of method depends on the imposed test conditions. However, because of the difficulties in interpreting measurement of voltage and impedance at microwave frequencies and above, thermal instrumentation measurements are often used to calibrate rf detector measurements, which are made using standard electronic circuit techniques. Consequently, more detailed discussion is devoted to thermal instrumentation.