ASIS International (ASIS) Professional Certified Investigator Practice Exam

What is typically the primary ignition source in explosive devices?

1. Friction

2. A spark

3. Heat

4. Pressure

The correct answer is: A spark

The primary ignition source in explosive devices is typically a spark. This is because most explosives require a significant amount of energy to initiate the chemical reaction that leads to an explosion. A spark can produce the necessary energy to ignite the explosives; it serves as a sudden and intense energy release that can effectively trigger the reaction. In many cases, manufacturers design explosives to be sensitive to a variety of initiation sources, but a spark is particularly effective. For instance, electrically initiated devices often use a spark plug or a similar mechanism to generate the ignition. This is largely due to the fact that a spark can easily penetrate through the safety barriers that are built into the explosive materials, allowing it to initiate the explosive reaction safely and predictably. While friction, heat, and pressure can also contribute to the ignition of explosives under certain conditions, they do not represent the primary means of initiation observed in most explosive devices. Friction can create a spark but is generally not reliable as a standalone ignition source in planned detonations. Similarly, while heat and pressure can affect explosive compounds, they require specific conditions to lead to ignition, whereas a spark provides a more direct and controlled form of initiation.