What is the best method for testing the time for a fuse?

• A. Take a 4 foot section of fuse, notch start and finish, light fuse with PWI, observe fuse spit out of notches; 3 feet between notches; 6 inches between each end
• B. Weigh the fuse after burning
• C. Light the fuse with a cigarette lighter
• D. Use a fuse with a timer device

Answer: (C)

The key idea is that fuse time is measured by watching how long it takes the fuse to burn, which reflects its burn rate. The direct, simplest way to capture that is to ignite the fuse with a flame and time the burn from ignition to completion. Lighting the fuse with a cigarette lighter gives you an immediate, observable start and a clear end point, so you can measure the delay accurately with a stopwatch. Other methods don’t provide a reliable or practical measure of burn time: weighing after burning doesn’t track the actual burn duration, and using a timer device introduces extra equipment and calibration that isn’t necessary for determining the fuse’s burn time in most testing scenarios.