Obviously it's easier to get the arm over the line faster in a sprint, but am unsure if that makes it harder to be "read" by the scanner 2 to 3 feet above it.
>
>
>
>
Triathlon Forum
Login required to started new threads
Login required to post replies
Re: Would the chip be best worn on the wrist? [dr.tri]
[ In reply to ]
the chip really does need to be as close to the line (low down) as possible! If you put it on your wrist, it will likely not register.
Re: Would the chip be best worn on the wrist? [dr.tri]
[ In reply to ]
If magnetic fields didn't decrease via 1/r^2, sure. Regrettably, they do.
-Jot
-Jot
Re: Would the chip be best worn on the wrist? [dr.tri]
[ In reply to ]
Would the chip be best worn on the wrist?
no. don't believe just me. listen to ChampionChip.
"The reading distance of the ChampionChip System is limited. The antennas are embedded in the red mats on the road. Therefore the chips should be located as close to the mats as possible on the body of the participant. In cycling events the chips should be located as close to the mats as possible on the frame of the bike."
and the best line...
"Do not cross the systems by walking on your hands. Your chip will not be read."
gigig
Train hard...race well.
www.jimmishler.com
"Jim, I happen to agree with you" DougStern
no. don't believe just me. listen to ChampionChip.
"The reading distance of the ChampionChip System is limited. The antennas are embedded in the red mats on the road. Therefore the chips should be located as close to the mats as possible on the body of the participant. In cycling events the chips should be located as close to the mats as possible on the frame of the bike."
and the best line...
"Do not cross the systems by walking on your hands. Your chip will not be read."
gigig
Train hard...race well.
www.jimmishler.com
"Jim, I happen to agree with you" DougStern
Re: Would the chip be best worn on the wrist? [Jim Mishler]
[ In reply to ]
The proximity necessary for reading the chip explains the missing bike splits in some results... did have a dead chip once- it's like you don't exist until photos,your competitors, and the finish films verify your finish.
>
>
>
>
Re: Would the chip be best worn on the wrist? [gamebofh]
[ In reply to ]
nerd question: what does r in that equation stand for?
Re: Would the chip be best worn on the wrist? [dr.tri]
[ In reply to ]
Here on ST they are traditionally worn on the shoulder.
Re: Would the chip be best worn on the wrist? [XXXXXXX]
[ In reply to ]
The 'r" stands for radius. The magnetic field force decreases exponentially as the distance (radius) from the source increases. I once watched a guy in front of me jump up and click his heels as he crossed the line. I was at once amazed by his "hops" at the end of the race and dismayed by the fact that he had that much energy after beating me. His time did not show up in the results!
http://stlifeontherun.blogspot.com
Official Polar Ambassador
http://stlifeontherun.blogspot.com
Official Polar Ambassador
Re: Would the chip be best worn on the wrist? [chemteach]
[ In reply to ]
Exactly right. Electrical fields diminish as 1/r, but magnetic are 1/r^2.
Since these typically work by measuring the changes induced in a magnetic field
that r^2 really matters. :)
-Jot
Since these typically work by measuring the changes induced in a magnetic field
that r^2 really matters. :)
-Jot
Re: Would the chip be best worn on the wrist? [gamebofh]
[ In reply to ]
Maxwell is rolling over in his grave about now...
Both E and M fields obey inverse square laws from point sources. But, you could argue that the timing mat is better approximated by an infinite strip, so both fields would then be 1/r.
"100% of the people who confuse correlation and causation end up dying."
Re: Would the chip be best worn on the wrist? [MOP_Mike]
[ In reply to ]
Maxwell is rolling over in his grave about now...
Both E and M fields obey inverse square laws from point sources. But, you could argue that the timing mat is better approximated by an infinite strip, so both fields would then be 1/r.
I was relying on my memory of math from physics from 20 years ago.
I will now, stop typing, get out my shovel and dig so I can roll Maxwell back over. :)
-Jot
Both E and M fields obey inverse square laws from point sources. But, you could argue that the timing mat is better approximated by an infinite strip, so both fields would then be 1/r.
I was relying on my memory of math from physics from 20 years ago.
I will now, stop typing, get out my shovel and dig so I can roll Maxwell back over. :)
-Jot
LOL. ;)
I thought about it a bit more after your post, and I'm not sure what the field really looks like around a timing mat because we don't know the geometry of the sensor -- is it a big solenoid? a really fat dipole? Who knows?
"100% of the people who confuse correlation and causation end up dying."