[xxs]

>Let’s say real times were 58.994999 and 58.995000 seconds.

How do you achieve a million frames per second? Even analog input (like touching - which would be capacitive [hence more tolerances]) will have a very hard time registering that, just based on cable and PCB traces length, temperature differences (which affect silicon and resistance in general). 7 digit precision is a non-trivial task for non-controlled environment. For example 8.5 digit voltmeters take one 1 minute for a single measurement and they have to have extremely good temperature controls.

Then for the microsecond precision you have to consider the speed of sound just to propagate to participants to hear the gun.

[sokoloff]

They’re not hypothesizing a measurement device recording those times and then rounding. They’re just setting up a “let’s take as a given that this is what really happened in the world” and asking what errors our processes could do if we do a series of imprecise measurements and then compare those measurements.

Side note: my HP 3458A can do a small handful of 8.5 digit DCV measurements per second.

[xxs]

>my HP 3458A can do a small handful of 8.5 digit DCV measurements per second.

I thought they had like 100k samples a second. Is it really sufficient for 8.5 precision?

Edit: perhaps measurement should be confined only to relative finish between the participants, e.g. finish within 1ms should be considered the same (regardless if they fall in the same hundreds of a second bucket)

[sokoloff]

I don’t keep mine in cal (or even powered up all the time), so I can’t claim full volt-nut status here, but my understanding is the 100K/sec 4.5 digit measurement rate is limited by communications not by sampling rate. (The 5.5 digit rate is 50K/sec, implying the 4.5 digit rate limit is not in the measurement but more likely in the GPIB.)

On thing I know with perfect precision: HP/Keysight knows more than me about this. :)

[cameron_b]

interestingly enough, for stage races, that is how things work to some degree for the "pack" finish, just not the guys going for the day's podium