Question about how foil timing is applied...

[ThatReallyHurt]

Wasn't sure if I should put this here or in the Fencing area...

I'm looking at the timings listed on the FIE site for foil. It says 13-15ms for "sensitivity of the apparatus" and 275-325ms for "time for double hit".

What I'm wondering is whether the timer for the double hit starts immediately when the foil tip is depressed, or does it start once the box has registered a hit (seen the tip already depressed for the full 13-15ms)?

Similarly, does the fencer making the second hit have to have completed the hit (had the button depressed for 13-15ms) by the time the double hit timer has run out, or is it only necessary to have the tip depressed immediately before the double hit timer runs out?

Any thoughts?

[Purple Fencer]

I would guess it starts the moment electrical contact within the tip is broken...

[EricS]

The lockout timer starts after the foil tip has been depressed for 13-15ms. In order to get his light to go on, the opponent must depress his tip at least 13-15ms before the lockout timer runs out.

Why? The original foil scoring machines used standard industrial control relays. The off target circuit for each side used a relay which was normally energized. After an off-target hit, it could take several milliseconds for the magnetic field to collapse and for the switch contacts to close, enabling the lockout timer.

[KD5MDK]

Er, that's not the reason for the 13-15ms debounce time, as the previous official debounce time (prior to 2004 Experimental) was 1-5ms.

[keropie]

I would expect that what the FIE had intended is that the lock out timing start with the end of the 15ms contact (i.e., the event which causes light one) and in order for the second hit to count the event (the 15 ms contact) of fencer two has to be completed by the end of the lock out. But that's just what I expect.

[EricS]

To clarify my previous statement, the comment about the timing based on the relay scoring machine applies to the 1-5ms valid time and the 2-10ms nonvalid time. The explanation quite logically extends to the 13-15ms timing.