Deceleration device means any mechanism that serves to dissipate energy during a fall.
Deceleration distance means the vertical distance a falling employee travels from the point at which the deceleration device begins to operate, excluding lifeline elongation and free fall distance, until stopping. It is measured as the distance between the location of an employee’s body harness attachment point at the moment of activation (at the onset of fall arrest forces) of the deceleration device during a fall, and the location of that attachment point after the employee comes to a full stop. It is the critical link in the fall arrest system. That’s why it’s important to make sure you’re using the right one every time