What are the five periodicities for taking a lube oil sample?

The correct option outlines key intervals related to operational protocols for taking lube oil samples. Lube oil sampling is a critical procedure as it helps monitor the condition of the oil and the health of the system it lubricates.

Taking a sample 24 hours prior to operation allows for testing the oil condition after it has sat for a while, ensuring that contaminants settle and the sample is indicative of the system status just before use. Daily sampling can identify trends and detect issues early on, which is particularly vital in the high-demand environments where gas turbine systems operate. Sampling before an auto start helps in assessing the oil condition immediately prior to operation, ensuring that any contamination or degradation is detected and managed promptly. Additionally, noting samples upon receipt is essential for maintaining quality control, as it provides a reference point for the oil's initial condition before it is integrated into the system. The inclusion of NAWC code 615 signifies adherence to standardized procedures set by maintenance and operational guidelines, which reinforces the importance of following established protocols in military and naval contexts.

This response outlines why the indicated choice correctly highlights the necessary practices for effective lube oil sampling, ensuring machinery operates reliably and efficiently.