[palmag]

Hi everyone,

Stumbled across this forum recently and I could not help myself from asking this question. I've owned my PRS 200 for over 8 years now and I'm still madly in love with, one thing though that has intrigued me over this time are the numbers inside the seconds graduations around the circumference of the face? what do they mean? how are they used?

Here's a link to the model watch i own.

http://www.idealdeal.ch/images/Tissot-PRS-200-T17148653.jpg

 

[LUW]

It's a tachymeter.

 

[palmag]

It's a tachymeter.

Thanks LUW!

That solves my question!

...how does it work?

 

[ohmegah]

Thanks LUW!

That solves my question!

...how does it work?

It is simply a graduated scale that enables the user to measure elapsed time over a set distance. Your's does not explicitly say "Tachymetre", so it's hard to tell what the scale is graduated to (kilometres or miles). There are also scales for measuring elapsed time over an imperial distance ("Tachymiler") fuel consumption, pulse rate and many others. Here are some examples:

This Omega Speedmaster has a scale graduated for kilometres. You engage the chronograph at metre zero, and stop recording elapsed time at kilometre 1. The scale will give you your average speed over 1000 metres.

This Tissot does the same calculation. It's hard to tell from your photo where the numerals on the scale are positioned, so it's difficult to tell if yours is calibrated for miles or kilometres. My guess is kilometres. I'll let you do the comparisons and make your own evaluations as to what yours is for.

Here's a multi-function dial with dual scales; a tachymetre and pulsometer:

There are many other scales incorporated into a myriad of styles by other manufacturers. Some of the most famous are the Breitling Cosmonaute and Navitimer, Ikepod Megapode and Hemipode who's dials require more discussion than I can possibly understand or try to explain...

Hope this helped!

Best,
Wallace

 

[LUW]

Thanks LUW!

That solves my question!

...how does it work?

Wallace already explained it, but if you click on the link in my post you will see how Wikipedia explains it.

 

[palmag]

ohmegah & LUW
Many thanks for your detailed explinations, I believe my watch is scaled for Km's.