Which of the following is NOT included in the list of discrepancies requiring instrument replacement?

The correct answer is that a cracked case is not included in the list of discrepancies requiring instrument replacement. This indicates that while a cracked case may be a concern, it does not necessarily impact the instrument's functional performance or accuracy in the same way that other issues do.

In contrast, discrepancies such as leaking at the line B nut, a cracked glass, or an instrument that will not zero out directly affect the safety, reliability, and precision of the instrument's readings. For example, a leak can compromise the instrument’s ability to maintain pressure, a cracked glass might impact visibility or allow contaminants to enter, and an instrument that cannot be zeroed suggests a fundamental calibration issue that could lead to incorrect measurements. These kinds of discrepancies demand immediate attention and often necessitate replacement to ensure operational safety and effectiveness.