How Does a Daytona Tachymetre Work?

[Chiboy]

I did a quick search here but couldn't find what I'm looking for. As I sit here awaiting a Daytona-C, hopefully this year, I have immersed myself in TRF. It is a wee bit addictive.

Anyway, I thought I should know a bit about the functionality of the Daytona, despite the fact that I, like many owners, probably will not use the stop watch feature very often. But I feel like I would like to know how the tachymetre works. It isn't intuitively obvious when I look at the dial, but I know I've read that it can estimate speeds up to 400 mpk/kph. So how does it do that?

[Tools]

They all work the same..

We have the various kinds of Tachs explained in detail in the Omega Forum since the Speedy used to be the most discussed.

http://www.rolexforums.com/showthread.php?t=36345

[Chiboy]

Originally Posted by Tools

They all work the same..

We have the various kinds of Tachs explained in detail in the Omega Forum since the Speedy used to be the most discussed.

http://www.rolexforums.com/showthread.php?t=36345

Ah, thanks. That was simple enough.

[RickR]

Computes the equation: T=3600/S

where 3600 = number of seconds in an hour
and S = time in seconds of the event you are measuring.

Example:
1 mile/kilometer/furlong in 25 seconds

T = 3600/25
T = 144 (mile/kilometer/furlong per hour)

[AK797]

Start the chrono, after 1 KM/mile, stop it and the Tachy will give you the speed.

[Chute]

Originally Posted by AK797

Start the chrono, after 1 KM/mile, stop it and the Tachy will give you the speed.

Yes. Try this.

On most interstate highways in the USA there are mile markers. Start the Chrono once you pass a mile marker and stop it when you hit the next mile marker. The tach bezel will tell your speed in mph.

I've used it on our Texas highways that are 85mph and its cool to set the cruise control at 90 and confirm the speed mechanically.

You can see it a well designed tool because you can click the Chrono buttons and read the mph without taking your hand off the wheel, assuming your watch hand is on the wheel

[masyv6]

Originally Posted by Chute

Yes. Try this.

On most interstate highways in the USA there are mile markers. Start the Chrono once you pass a mile marker and stop it when you hit the next mile marker. The tach bezel will tell your speed in mph.

I've used it on our Texas highways that are 85mph and its cool to set the cruise control at 90 and confirm the speed mechanically.

You can see it a well designed tool because you can click the Chrono buttons and read the mph without taking your hand off the wheel, assuming your watch hand is on the wheel

As long as we aren't talking about screw down pushers

[Chiboy]

Originally Posted by masyv6

As long as we aren't talking about screw down pushers

[sutats]

An Alternative Use For a Watch Tachymeter: https://www.youtube.com/watch?v=zVjmQh_qzgY

[MrHungryMonkey]

Originally Posted by sutats

An Alternative Use For a Watch Tachymeter: https://www.youtube.com/watch?v=zVjmQh_qzgY

Thanks, that was great!

[Wingman244]

Has anyone ever used the tachymeter scale in concert with their chrono function? I love chronos - I have a Omega Speedmaster with a bezel tachymeter scale and a Zenith Striking Tenth with no tachymeter. It seems to be "required" in most sport chronographs but I kind of view it as useless. What would would be better as a replacement? I think a moveable bezel with minutes (like a diver) would be far more useful. But I have to admit that a chrono without a tachymeter is missing something.

[Old Expat Beast]

Originally Posted by Wingman244

Has anyone ever used the tachymeter scale in concert with their chrono function? I love chronos - I have a Omega Speedmaster with a bezel tachymeter scale and a Zenith Striking Tenth with no tachymeter. It seems to be "required" in most sport chronographs but I kind of view it as useless. What would would be better as a replacement? I think a moveable bezel with minutes (like a diver) would be far more useful. But I have to admit that a chrono without a tachymeter is missing something.

For me a rotating 12 hour timezone bezel is much more useful than a tachy.

[Wingman244]

Originally Posted by Old Expat Beast

For me a rotating 12 hour timezone bezel is much more useful than a tachy.

Nice watch, I agree. I could really use the rotating bezel on a daily basis. It would be great to help when you are timing something that is multi-hour in duration. (It would need to be 60 or 120 clicks, not 12 or 24 - to exactly set to the hour hand.)

Tachy - not so much.

[GMT13]

One thing people don't realize is that you can know speed to measure distance - the opposite of what was previously said. For example: on a plane or in a car, you know the speed, so just start/stop the chrono when it gets to that mark and you have traveled one unit of the speeds measurement.

Another interesting way to use it is to count how many times you can do something per minute or per hour.

But I agree, it's more gimicky than functional, and I would rather have a 12 hour or 60 unit rotating bezel