How is an OBA timer set to start its countdown?

Setting an OBA (Out Breath Apparatus) timer is crucial to ensure that the equipment functions effectively during operations. The correct method involves first turning the timer to 60 seconds and then rotating it back to the desired 30 seconds.

This approach is essential because starting at 60 allows the timer to reset properly and establish a reference point, ensuring that the countdown begins accurately from the intended time. By moving the timer to 30 seconds directly from an inactive state may not guarantee that it has reset correctly, which could lead to inconsistencies in calculations regarding the available air supply. Setting it to 60 seconds first ensures that the mechanical components are properly engaged, thereby giving a clear and precise countdown.

Using this method also aligns with standard operating procedures which emphasize the importance of proper reset sequences to avoid any potential operational hazards. This helps personnel manage their air consumption strategies effectively, maintaining safety during extended operations in hazardous environments.