The AMPTEC 640N Igniter Tester was designed for military ordnance programs as a ruggedized product that can safely measure resistance on explosive devices such as squibs, flares, and explosive bridge wire. With multiple safety approvals, a durable/waterproof yet compact case, self-contained DC milliammeter and test resistors, and a shielded Faraday cage design, the 640N is among the safest and most self-aware products of its kind.