# Chronograph - Split Time reading... explain this like I am 5 years old.



## DownTownAndrew

So my watch has a Chronograph, and I understand the basic concept of it being a stopwatch. 
So lets say there is a racer and I am going to record two laps..... 

Ok I can understand the recording of the first timed lap.... 
for example the stopwatch was stopped at 30 seconds ( 1st time)..... I write down the time, the second hand is still at the 30 second mark... because I pressed the lower button... instead of resetting it. 

and here comes the runner again for his final crossing of the finish line...I now click the lower button again.. since he is passed me again.. and the chronograph spins up... and catches... the time.

At this moment... my ADHD kicks into overdrive.... 
if the racer is passing me... I need to accurately look at when he crosses the finish line... at that moment *click*... the second hand is going to sprint forward to catch the lapse in time, right? But its also going to continue recording time after is sprints forward to cover the elapsed time. 


do I stare at the watch to catch exactly when the chronograph begins retiming ( which to me signifies the "END" of the timed event of the second lap) 

second hand is on 30 seconds.... then lets say it springs ahead to the 15 second mark ( a total of 45 seconds for the second lap, right?) 


how on earth will I get an accurate second recording of time to the tenth of a second if needed. IF after it sweeps to catch up the elapsed time... and continue recording time.. till I stop. 

I think I am over thinking this.. there has to be a easier way. Especially in a time critical recording.


----------



## spain72

I will let you know. Just give the time to find out the right answer...


----------



## The Guvnah

I've got a chronograph and never recorded a split time event in my life but I chucked my Pulsar at my 6yr old to see if he could figure it out, :-d My understanding of the split timing function is thus. At your first push to record the moment yer man passes the line on his first lap the chrono will stop giving you the first lap time. Note it down. The timing is still going on within the movement but disconnected from the hands at this point. Hit the button to resume and the hands will race round to their catch up point and then continue in _real_ time until the runner crosses the line to complete his second lap. Hit the button and the hands stop again showing the *accumulated* time for the two laps. Scribble it down. (The watch is still timing internally if he decides to go for a third and personal best.) Now it's just a matter of subracting his 1st lap time from that 2 lap accumulated running total to give the time for the 2nd lap. At the completion of the third lap you hit the button again and now you've got the time taken to do the 3 laps. Subract the 2 lap total from this and it'll give you the time taken to do the 3rd lap and so on and so on. It'll keep counting internally for as long as he's on his feet or you hit the reset pusher. So long as he hasn't completed another lap in the 10 seconds it takes to note and record each timing and for the stopped hands to catch up to real time you're OK. If he does a lap within that time he requires immediate testing for stimulants. Does this sound correct?


----------



## spain72

Basically, in the history of sport, chronography and Official Timekeeping there are thousands of PROVED errors because of the "human factor". 
By the way, to become an Official Timekeeper you still need to pass very hard exhams and selections and during competitions of the past it was very easy to see TEAMS of Timekeepers working together. 
Thanks God the Quartz-Era brought superior accuracies in timing (not only the collapse of the Swiss mechanical watch industry) and the analog-quartz watches positively reduced the impact of the "human factor" on athletes carreer!  
I think it's only a matter of philosophical approach to the argument, then. Not a matter of childish questions.
"Elementary" questions as yours are the basis of the development of Progress and Cooperation: could you ever believe it?

Some helpful links and infos found on the Net:
- Split-seconds chronograph - Fondation de la Haute Horlogerie
- "Chronographs: To Stop Time" by Lang and Meis: interesting book describing everything about chronographs.
- Split Second Hand:an additional second hand, located over the actual chronograph hand. It serves, for example, for clocking intermediate times and can be stopped with help of a special mechanism independently of the chronograph. Then after the intermediate time has been read (and recorded), the split second hand can be made to catch up with the chronograph hand. This process can be made as often as is wished. Zero-setting the split second hand independently of the chronograph hand is not possible. Wristwatches with split second chronograph features came on the market around 1920. 
- http://www.omegawatches.com/fileadmin/basic_functions/Guide_5110-20-00_English.pdf
- Parliamo ancora di Orologi ! il Cronografo RATTRAPANTE


----------

