A labyrinth seal impedes leakage flow though a gap between confronting static and moving parts in a turbomachine. The helmet mount includes an adjustable socket assembly for mounting goggle horns with varying dimensions therein, and a break away latch assembly in the lower socket that allows a goggle horn to be removed if a certain predetermined force is applied to the night vision device. The safety guard moving mechanism further includes a control for determining the size of the web reel and operating the moving mechanism to position the finger sensor. The device may determine a set of dominant terms based on performing the similarity analysis.