On Fri, 15 Sep 2000 10:49:21 -0700,
"Conway" <[EMAIL PROTECTED]> wrote in part:
>Murphy is right .. If you start the watch when you
>actually see the smoke from the gun .. And then stop
>it when you actually see the body cross the line
>then you are timing accurately and should be within
>hundredths of the actual time .. I am usually
>within .02 +/- in any given race ..>
Unfortunately the accuracy of your manual timing
will also depend on the accuracy of your watch.
If it is one of the digital timers advertised
nationally (in the US and elsewhere) it will not
be anywhere near accurate.
Tests on dozens of samples of several brands of
digital watches showed errors of up to 10/100ths
within a range of 14/100ths. These errors were not
in long-term accuracy. They were in the programs
controlling the start/stop/counting operations.
Consequently they affected all distances equally -
whether 10,000m, 100m, or 1m.
The distributor of two brands (advertised in a
well-known magazine) was told about these
discrepancies by an irate customer. His reply was
"I'm not surprised" !
So if the time on your digital hand timer agrees
with the fully automatic time, your timing
technique is almost certainly wrong!
For anyone who finds these results hard to believe,
full details are available. The tests were done
with a satellite-controlled clock having an r.m.s.
accuracy of 1/10,000,000 second.
P N Heidenstrom
