Tip & How-To about Watches

# TACHYMETER/TACHOMETER - how to use it.

Many of watch brands has outer bezel ring calibrated as TACHYMETER/ TACHOMETER. In simple words this is SPEEDOMETER on your wrist, like in your car. The only difference is: it does not work automatic, but you have to have some maths basics in your brain to make work it.
The main thing is: As second is taken as measuring point (any wristwatch is moving sec by sec, min by min, hr by hr and so on), there is no actual possibility to measure speeds less than 60 km/h. This is because our time is divided to hours, minutes and seconds (1 hr=60 mins= 3600 secs), but ordinary watch on your wrist can't count smaller than a second, so, the starting point still is 60 for the majority.
The best watch tachymeters are producing/manufacturing BREITLING, as they have very long relationship with aviators all over the world. Braitling watches can count up to 1/10 of second.
OK, here is the link to learn basics of how to use tachymeter:
http://www.mydigitallife.info/2006/12/10/how-to-use-tachymeter-function-on-watch-bezel-usage-instruction-and-definition/

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## Related Questions:

### how do I use the moveable outer numbered ring on the t49825dh?

The numbered bezel can be used by divers to measure elapsed time on their oxygen supply. Place the zero where the minute hand is now and you'll know when 20 or 30 minutes have passed when the minute hand reaches bezel number 20 or 30.

In the same way, you can use the bezel to tell when 30 minutes have passed on your parking meter if you simply put the 0 on the minute hand when you leave the car. When the minute hand reaches the 30 mark, a half hour will have passed.

Typically, the bezel only turns counterclockwise to keep the wearer from bumping and changing the elapsed time number. On some less expensive watches, the numbered bezel does not turn and is decorative only.

Oct 23, 2014 | Timex Tiex en T49825DH Expedition Military...

### HOW USE TACHYMETER & WHAT TACHYME3TER MEANS

A Tachymeter helps you estimate the speed you are going.

It uses the basic formula that speed = Distance/time

Here is how to use it: (For the full article see the link below)

To use tachymeter, simply start the chronograph or stopwatch when the object measured passing the starting line. When the object reaches the next mile or kilometer marker, stop the chronograph or stopwatch. The point on the tachymeter scale that adjacent to the second hand of the watch indicating the speed (in miles per hour or kilometers per hour) of object traveling between the two points.

For example, we want to measure the average speed of a vehicle is moving. Start the chronometer or stopwatch function when the car passes the starting line, and stop the timer after the vehicle traveled exactly 1 mile or 1 kilometer. Then look at where the chronometer hand (the second hand of the watch) is pointing to, and get the reading or value of the corresponding number at the tachymeter bezel or dial. Let's say the stopwatch stop at 3 o'clock position, meaning 15 seconds had elapsed for the car to travel 1 mile or 1 kilometer. At 3 o'clock position, the tachymetre value shows that number of 240, which means the average speed of the vehicle was 240 mph or km/h.

### Source(s):

http://www.mydigitallife.info/2006/12/10...

Apr 02, 2013 | DKNY NY5045 Watch for Men

### how do you use the tachymeter

http://www.mydigitallife.info/2006/12/10/how-to-use-tachymeter-function-on-watch-bezel-usage-instruction-and-definition/

Aug 06, 2010 | Timex 22991 Wrist Watch

### The black plastic ring, w/ white markings (bezel ?), that goes on the metal (dial) which moves around, fell off. Is this part avail., and if so, for how much ?

This part is called the bezel, you are correct. They are available to buy as a separate item for certain watches, but not all. You didn't mention what type of watch it was. Most major brands, like Rolex, Omega, Tag Heuer etc all sell bezels for their watches, brands though like Diesel, Rotory, Seiko etc, do not sell bezels as a stand alone item. Should you wish to let me know the make and model of the watch, I will see if I can obtain one, or failing that I will see if I have one that will fit.

Apr 24, 2010 | Casio Marine Gear AMW320D9EV Wrist Watch

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