What modification of the test procedure must be done to prevent "brittle fracture failure"?

Selecting the test medium based on expected low temperatures and monitoring ambient temperatures carefully is crucial to preventing brittle fracture failure. 'Brittle fracture' often occurs in materials at low temperatures when they become more susceptible to breaking without deformation. By choosing a test medium that accounts for these low-temperature conditions, engineers can ensure the materials are tested in a way that reflects their performance in real-world conditions. Monitoring ambient temperatures is also essential since temperature fluctuations can significantly impact the material properties and the results of the test, thus mitigating the risks associated with brittle fracture failure in critical systems.

Utilizing the other options could lead to suboptimal testing conditions and increase the likelihood of brittle fracture occurring, as they do not address the importance of temperature in material integrity testing.