How does a chronological watch work

If you want a nice view of the chronograph through the display back, an integrated movement is the way to go. Some feel that in all but the finest executions, a modular construction will be less precise. The chronograph seconds hand may jump or stutter when started, the continuous seconds or the minutes hand may jump slightly when the chronograph is activated even the date disk may move slightly , and the feel of the push-piece is not as smooth and buttery.

As noted above, modular designs can also generate more amplitude-reducing drag when the chronograph is engaged. The integrated model also used a vertical clutch — see below. They include a high jewel count, no chronograph components visible through the display back, a date display that sits down in a hole and not directly below the dial, and a crown that is not on the same horizontal plane as the chronograph buttons though some brands try to disguise this with oversized crowns, push-pieces, and guards.

Imagine what would happen if you could activate the reset mechanism while the chronograph was running. To prevent this and other disasters, chronographs employ systems to coordinate actions initiated by the push-pieces.

As you might expect, there are different systems, and each has its supporters and detractors. The traditional system, favored by purists, is the column wheel, so named because the key component looks like a wheel lying on its side with a series of small, vertical columns rising up from it. Each push of a button causes the wheel to turn, and as it turns, the columns, and the spaces in between, move in small increments. Column wheels are traditional, expensive to manufacture and to adjust, and difficult to service.

They also look great, and they provide very smooth push-piece feel. The new system functions much like the traditional one, with an eccentric cam a thin piece of metal with an irregular shape replacing the column wheel. Cam systems are generally less expensive to manufacture, easier to adjust, easier to service, and not as nice looking.

In use, cams generally perform as well as column wheels. Chronographs powered by the Lemania Caliber , with cam switching, were certified by several countries for military use. When the Swatch Group announced that it would halt Caliber production, watch manufacturers using the movement objected, saying it was the only caliber that could withstand large shocks without the chronograph seconds hand stopping.

The was eventually discontinued and replaced by an ETA caliber. Finally, the ETA , which is also known for being rugged, uses cam switching. If you care about tradition, a nice view through the display back, and the approval of purists, the column wheel is for you. The traditional system uses horizontal or lateral coupling to transmit energy. When the start button is depressed, a wheel mounted on a moveable bridge or lever slides horizontally to link the fourth wheel, which rotates once per minute, with the chronograph center wheel, which drives the chronograph seconds hand.

The intermediate sliding wheel is required because if the fourth wheel meshed directly with the chronograph center wheel, the chronograph wheel and the seconds hand it activates would run counterclockwise. The horizontal meshing system is aesthetically pleasing because it enables the owner to watch the chronograph engaging and disengaging. However, meshing teeth can cause the chronograph seconds hand to jump when it starts, and because the teeth used for chronograph coupling have a different shape, or profile, than teeth used for continuous power transmission, regular or continuous chronograph use can cause the teeth to wear.

The other main contender in this arena is known as the vertical clutch. Though not as aesthetically pleasing because the chronograph engagement takes place largely out of sight , this system offers some advantages. It reduces chronograph drag, the chronograph seconds hand does not jump when started, and the chronograph can run continuously without causing excessive wear.

The drawbacks include cost, poor aesthetics, and the fact that the vertical clutch can be difficult to service. The higher the frequency, the smaller the fractions. So, as the average frequencies for wristwatch movements have increased over the years, chronographs based on those movements have become able to measure smaller and smaller fractions of seconds.

Movement frequencies are often expressed in vibrations per hour, or vph. Viewed from above, the balance wheel swings back and forth, left and right. Each swing to the left or to the right is a vibration. Each vibration, or beat, causes the seconds hand to make one jump forward. The most common frequency for modern mechanical movements is 28, vph.

To calculate how many vibrations that is per second, divide that rate by 3,, which is the number of seconds in an hour remember that vph is vibrations per hour. Having mastered this bit of math, it is important to keep in mind that the movement frequency does not always translate directly to the motion of the chronograph seconds hand. In recent years, some manufacturers, notably TAG Heuer , have started producing chronographs with two mainspring barrels, two wheel trains, and two escapements that run at different frequencies.

The timekeeping escapement can tick along at a leisurely frequency meant for movements that run for years on end offering low wear and a long power reserve , while the chronograph escapement can operate at a much faster frequency that allows it to measure hundredths or thousandths of a second and beyond.

Anything one watchmaker can invent, another can make more complicated, which leads us to some exotic forms of the chronograph: the flyback and the rattrapante. The flyback is much more useful when measuring fractions of a second is not required. For example, if a pilot has to execute a series of turns at specified time intervals, he can quickly reset and restart the chronograph before making each turn.

Another exotic option is the rattrapante chronograph, also known as the split-seconds or doppelchronograph. These watches have two chronograph seconds hands, one on top of the other. The extra seconds hand allows the timing of a second event, or splits within a single event, though with one significant limitation we will discuss momentarily. Pushing the rattrapante button again causes the rattrapante hand to catch up to the primary chronograph seconds hand, which is how you time splits in a longer race.

For example, in a one-mile race, you might press the rattrapante button each time the runner passes a quarter-mile marker, reading the time for that split. After reading the time, you can press the rattrapante button again to reunite the chronograph seconds hands, until the next quarter-mile marker comes up. The limitation is that the rattrapante hand has no minutes counter of its own. So, you can time two events, or splits within a longer event, as long as the rattrapante hand does not have to measure more than one minute.

The four chronograph hands two seconds and two minutes also have flyback functionality. And, the movement has two column wheels — one for stop-start-reset, and one for the rattrapante functions. Some of us want a date display, but the chronograph that has captured our hearts does not have one. That leaves the cellphone option, which, in our view, is acceptable, even for a true watch aficionado. Or, put a tiny bit of tape on the crystal to block the date.

Adding a scale to a chronograph dial or bezel expands the range of information the timepiece can convey. One set of scales is based on the relationships between time, speed, and distance — if you know two values, you can calculate the third, and the scale makes the calculation for you.

For example, a tachymeter allows you to calculate speed over a known distance, typically kilometers or miles. A simple example of tachymeter use involves determining the speed of a car, where time and distance are known. Start the chronograph when the car passes a mile or kilometer marker, and stop the chronograph when the car passes the next marker.

The tachymeter can only measure for one minute, and it is typically graduated to show only a certain range of speeds for example, between 60 and kilometers per hour. A telemeter allows the user to calculate distance based on known speed and time. The scale is graduated using the speed of sound through the atmosphere. The scale allows the user to determine the distance to an event that can be both seen and heard. The two most widely cited examples are lightning and artillery fire. The user starts the chronograph upon seeing the flash of light and stops the chronograph when he hears the sound.

Chronographs have to have additional systems and mechanisms to control each of the functions or complications of the watch. This is why chronographs are often more expensive than other kinds of watches. They have a lot more moving parts, and watchmakers have to make sure these mechanisms do not interfere with each other. Chronographs keep time in the same as any other watch, building tension on a mainspring that slowly releases to move the gears and keep time.

However, a chronograph watch has multiple systems within the timepiece to track different sets of time. Usually, there are at least two, if not more. One of the questions we get the most is how to actually make use of a chronograph watch.

Many people have them, but they end up just using them as a normal watch. The first and most common feature among all chronograph watches is a stopwatch. By using the two additional buttons on the side of the watch, you can start, stop, and reset this function. In some, this will be an extra hand that goes around the face of the watch, but typically this will use the dials on the face. The second hand will start counting first, followed by the minutes and the hours.

This may not seem very useful in the age of smartphones, but this was incredibly important for many people back in the day. Those in the military would use chronographs to time artillery strikes or to see how long it took to get from one place to another. A tachymeter is made as a rotatable bezel that is used to measure speed and distance. This was most commonly used by athletes timing their races. If you know the time and the distance, you can use the tachymeter to calculate your speed.

In addition, if you know time and speed, you can also use it to calculate your distance. The number on the tachymeter may not make sense initially, but there are easy formulas you can use to do your calculations.

There are some bezels that rotate, allowing the wearer to do multiple calculations simultaneously. When it comes to buying a chronograph watch, there are a few things you should keep an eye out for. Each of these will be important when choosing which watch you want to purchase. For example, all Jack Mason watches are made with sapphire crystal, genuine Italian leather straps , and come with a warranty for the lifetime of the watch. We want you to have a luxury watch that you can treasure and pass down to your children and grandchildren.

This just comes down to your personal preference. You can also use the tachymeter to tell how much work can be completed in an hour.

So, in theory, you could wrap 90 presents per hour. In order to use the tachymeter to measure distance, you have to know what speed you are traveling. Start at zero seconds and stop once the tachymeter reads your traveling speed.

Book a Virtual Appointment X. The Details January 21, Follow HSS. Using the Tachymeter to Measure Distance In order to use the tachymeter to measure distance, you have to know what speed you are traveling.