Timing the operation of control systems associated with rotating equipment

The problem of the exact time of operation of a contactor or braking device in a sequence is a common one, and by the application of the technique outlined in the paper, with simple apparatus times can be measured to better than one-thousandth of a second. The application of this technique to a variety of methods of stopping two-roll mills, as well as illustrating factors such as the time-constants of machinery, discloses some new mechanical problems about which very little is known, e.g. brake glide.