Which engineering control makes it that the laser cannot operate when the housing is opened or removed?

• A. MASTER SWITCH CONTROL
• B. SYSTEM INTERLOCKS
• C. BEAM ENCLOSURES
• D. PROTECTIVE HOUSING

Answer: (B)

System interlocks are the safety feature that directly prevents the laser from operating if the protective housing is opened or removed. They work by wiring a door or access panel sensor into the laser’s control circuit so that any opening immediately interrupts the laser emission or power, leaving the system in a safe, off state until the enclosure is closed and the interlock is reset. This fail-safe design ensures that the beam cannot be produced when someone could be exposed.

Master switch control only turns the laser on or off by user action and doesn’t automatically disable operation if the housing is opened. Beam enclosures and protective housing help reduce exposure, but without an interlock, simply opening the housing could still allow the laser to operate or fail to promptly shut down in an unsafe condition.