Glossary Terms - E

Electric Strike

A hardware device, which when activated from a remote location, releases the locking mechanism latchbolt and allows a door to open.

End of Line Resistor

Installed at the termination point of a monitoring circuit. It is used to determine if the wiring runs continuous and has not been cut.

Engineer's key

A selective master key which is used by various maintenance personnel to gain access through many doors under differen tMaster and Grand Master Keys. The key can be set to operate any lock in a master key system, and typically fits building entrances, corridors, and mechanical spaces.


Escutcheon (of a lock) – A Trim plate usually for a mortise lock, which covers door face cut-outs and incorporates the function holes for spindles, cylinders etc.

Exit Device

(See FIRE EXIT HARDWAREPANIC HARDWARE) – A door locking device with a pushbar or crossbar which, when pressed, allows instant exit (egress).

Extreme Temperature Fluid

Special hydraulic fluid which allows full valve function without readjustment when temperature varies by 50º-70º F.