When are non-restorable detectors required to be sent to a testing lab?

Non-restorable detectors are required to be sent to a testing lab after 15 years to ensure their reliability and functionality. This timeframe is crucial because detectors, particularly those used in critical safety applications like fire detection, may degrade over time due to environmental factors such as dust, humidity, and temperature variations. By sending them to a testing lab after this period, fire departments and facility managers can verify that the detectors are still operating within the required safety standards. This practice helps to maintain a high level of safety for occupants and ensures that the detectors will effectively perform their intended function in the event of a fire. The specified 15-year timeframe reflects both a reasonable lifespan for these detectors and the necessity for periodic testing to uphold safety protocols.