How to choose a mechanical stopwatch
Maximum period to be metered: 15 minutes, 30 minutes, 60 minutes
Minimum timing scale to which accuracy is required: 0.2 sec., 0.1 sec., 0.02 sec., 0.01 sec.
Most mechanical stopwatches are used to record a separate period of time that is not interrupted, a single button stopwatch fulfils this need.
The two-button stopwatch builds on this by adding a pause function and a separate zero return button to avoid misuse.
Single-button stopwatch: the only button to control the three-step chronograph action of "start", "stop" and "return to zero", as well as the winding function.
Dual-button stopwatch/pause and safe-return-to-zero function: if you need to record time periods with intervals, a stopwatch with a pause function can meet your needs.:
The top button controls the "start", "stop" and winding functions, while the side button controls the "return to zero". The "return to zero" operation of the side button can only be successful when the hand is stopped, which reduces the possibility of misuse.
Dual-button flyback stopwatch: the top button controls the "start", "stop" and winding functions, while the side buttons control the "return to zero". In order to satisfy special cyclic timing needs, unlike ordinary dual-button stopwatches, the stopwatch in chronograph mode can also return to zero and start a new cycle of timekeeping at the same time as the side buttons are released.