Yeah, pump until the bell stop.
If you poke in and no bell ring immediately, it means your tyres
are at least at the set pump pressure and no addition needed.
but having said that, the pumps somtimes leak quite bad, so they'll
never stop ringing.
If so and you don't wanna look for another pump,
take note of the bell ring frequency after you've set the pressure
before you pump.
So that when the bell ring at this this pre-pump frequency during
pumping, you know that you're done..
Cheers! 