i Register
In some senses, chronograph is marked as obsolete. Watch for register when choosing this word.
noun
A chronogram.
A device which marks or records time or time intervals.
A combination of a watch and a stopwatch.
Along this critical length Sir Nigel [Gresley], completely unmoved and in a very cheerful humour, came into my compartment and sat down next to me, with the immense chronograph in his hand that he had had made specially for speed recording; [...].
verb
To make an accurate measurement of the speed of a projectile.