Which of the following tests is NOT required for Special Form material?

The requirement for testing Special Form material in the context of nuclear gauge applications emphasizes safety and functionality under extreme conditions. Special Form materials are those that have been specifically designed and tested to ensure they remain intact and do not release radioactive material during incidents such as accidents or mishandling.

The tests typically required for Special Form materials include impact, heat, and percussion tests. These tests are conducted to verify that the material can withstand specific challenges without compromising its integrity.

For instance, the impact test simulates a scenario where the material might fall from a significant height, while the heat test assesses its ability to withstand high temperatures without degradation. Percussion testing evaluates how the material holds up under sudden impact or force, which could occur if the gauge were to be struck.

The weight test, which involves applying a specified load for a duration, is not a standard requirement for Special Form materials as it does not address the critical failure modes relevant to the integrity of such materials in safety applications. Therefore, this test is the one that is NOT required for Special Form material, making it the correct choice in this context.