How is the explosive strength of detonating cord usually expressed?

• A. In kilograms per meter
• B. In grams of PETN per meter or foot of cord
• C. In pounds per foot
• D. In liters per meter

Answer: (B)

The explosive strength of detonating cord is typically expressed in grams of PETN (Pentaerythritol tetranitrate) per meter or foot of cord. This measurement is crucial because PETN is the primary explosive used in most detonating cords, and its weight provides a standardized way to quantify the energy output and effectiveness of the cord in initiating other explosives.

By expressing explosive strength in terms of grams of PETN, it allows for precise calculations and comparisons between different types and brands of detonating cord, ensuring that the explosives team can select the appropriate product for their specific applications. Such specifications help ensure safety and effectiveness in blasting operations, enabling the right amount of explosive to be used for the task at hand.

The context surrounding the other options emphasizes their inapplicability to the specific standard used for detonating cord. For instance, kilograms per meter or liters per meter do not relate directly to the explosive content of the cord, and pounds per foot is not the conventional standard for explosives. Understanding why grams of PETN is the preferred measurement highlights the scientific basis for explosive effectiveness and safety in the mining and construction industries.