Which statement correctly describes the frequency and marking for element changes?

• A. Every 12 months; no marking required
• B. Every 60 months; stamp the date
• C. Every 24 months; write the date in the log
• D. Every 36 months; the month and year should be stenciled on there

Answer: (D)

Tracking when an element was last replaced and marking it directly on the element keeps maintenance clear and verifiable. Replacing the element every 36 months establishes a regular service window that helps prevent degraded performance while avoiding unnecessary replacements. Stenciling the month and year on the element provides a durable, at-a-glance record right where it’s needed, so inspections and audits can quickly confirm compliance without flipping through logs. This combination—a defined 36-month interval plus a visible date mark—ensures timely replacement and easy traceability in field conditions.