Which of the following impulse cartridges is not case grounded?

The BBU-63/B impulse cartridge is designed without case grounding, which is a significant characteristic for its function. This means that the electrical circuit for the ignition of the device doesn't rely on the case for grounding, allowing for a more stable and predictable operation. In practical terms, this design can enhance safety and reliability by minimizing the risk of unintended ignition due to case grounding issues.

In contrast, other impulse cartridges like the BBU-64/B, BBU-62/B, and BBU-61/B utilize a case grounding mechanism. This design can help ensure that the circuit is completed properly when the device is initiated, but it also introduces complexities regarding installation and handling requirements. Understanding the differences between these cartridges enhances a munitions systems technician's ability to choose the right impulse device for specific applications and ensures compliance with safety protocols.