How do maintenance manuals indicate which sections require calibration after service?

• A. They specify the required calibration procedures and reference instruments to be used.
• B. By listing a universal calibration table at the front of the book.
• C. By marking sections with color codes to indicate calibration.
• D. By referencing external vendor manuals for calibration.

Answer: (D)

Calibration requirements after service are shown directly within the maintenance procedure itself. When a section involves work that could affect measurement accuracy, the manual lays out the exact calibration steps you must perform, and it specifies the reference instrument or calibrator to use. This keeps the process traceable to approved standards and ensures that, once calibration is complete, the item meets its required accuracy before it’s deemed serviceable. The section may also note the target tolerances, any required post-calibration checks, and how results should be documented.

While external vendor manuals can provide detailed calibration methods, the key signal that a section requires calibration is the embedded calibration procedure and the listed reference instruments within that same section. A universal table, color codes, or relying solely on external manuals do not reliably communicate which sections need calibration after service.