The duration of each test shall be not less than how many minutes?

The correct answer indicates that the duration of each test should be a minimum of 15 minutes. This standard is important in mechanical testing because it allows sufficient time to assess the performance, integrity, and safety of mechanical systems or components. A test duration of 15 minutes strikes a balance between being long enough to gather reliable and consistent data, while also being practical for implementation in various settings, such as inspections and performance evaluations.

This duration ensures that all relevant factors can be monitored and measured effectively, contributing to robust results that verify compliance with safety and operational standards in the mechanical code. If tests were shorter, there would be a risk of incomplete assessments, potentially leading to unsafe mechanical systems being overlooked.