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How do chronographs work?

Chronographs work by helping you measure time intervals. Many watch manufacturers include them on their timepieces to add functionality and sophistication. (It’s always cool to have extra dials and gizmos whirring away in the background behind the regular clock face). 

Unfortunately, the word “chronograph” can seem a little complicated and put you off, especially if you’ve only just started investigating the world of watches. That’s why we’ve written this post. We explain how these handy mechanisms work and why you don’t need to be afraid of all those dials on your watch!

What is a chronograph?

A chronograph is a device that measures elapsed time (often on a wristwatch). Most have three dials – one for seconds, one for minutes, and one for hours. 

When the second hand counts to sixty, it clicks to zero, and the minute hand goes to one. Then, when the minute hand gets to thirty, the hour hand clicks to 0.5, and so on.

On wristwatches, you start the chronograph by pushing the crown, the part of the watch that sticks out next to “3” on the dial, between the pushers. To stop it, you simply push the crown again. 

When you push the crown, the second hand starts to move. It will continue circling its dial while the minute and hour dials count up. The chronograph makes it easy to see how much time elapsed instead of trying to work it out from regular watch movement. 

Chronographs are different from chronometers despite people using the two terms interchangeably. The latter is a watch that passes a series of Official Swiss Chronometer Testing Institute tests and meets OSCTI accuracy standards over 15 days. The former is not. 

How chronographs work

Watches have two sets of mechanisms: those responsible for the main watch movement and additional ones for the chronograph movement. Watchmakers make chronographs to operate independently of the primary watch movement, enabling you to track elapsed time accurately. 

Starting and stopping

Most chronographs have a start/stop button. On wristwatches, this is usually the crown. 

When you press the button, the chronograph will spring into movement until you press the button again. 

Clocks and watches with chronographs often have a reset button to wind all the dials back to their starting position. How this works depends on the manufacturer. For watches, most designs require you to pull out the crown with two clicks and use the top and bottom pushers to click the chronograph hands into the correct position on each dial. 

Chronograph hands and dials

Traditional chronograph hands have three dials: seconds, minutes, and hours. 

The second hand moves continuously, allowing you to determine more precise time intervals. It doesn’t offer the precision of a stopwatch, but it is suitable for many applications. 

The minute hand moves incrementally on most units, jumping discretely between marks on the dial. High-end watch manufacturers typically place thirty increments per revolution of the minute hand, designing it to land in the right place on the dial as the second hand passes through a full revolution. 

The hour hand completes classic three-dial chronographs and measures elapsed hours. Most chronographs go up to twelve hours. 

Type of chronograph

How a chronograph works also relates to the mechanism your watch or clock uses.

Some chronographs are manual winding. Owners must physically wind them up to load an internal spring to provide the energy they need to measure the elapsed time. 

Other chronographs are automatic. These are self-winding and use a motor powered by the wearer’s wrist movements to crank the mechanism. 

Finally, some modern watches have quartz chronographs. These use a vibrating quartz crystal to keep time and a battery for power.

Accuracy

Many people assume chronographs are exceptionally accurate. However, that’s not always the case. Only chronometers are certified to keep time accurately over several days. 

Chronographs can have high precision and low accuracy. That is, some mechanisms may provide you with readings to the nearest fraction of a second but get the time elapsed wrong. It is also possible for the reverse to be true: for chronographs to be excellent at measuring time elapsed, even if they only measure to the nearest second. 

What do people use chronograph watches for?

Chronograph watches became popular because of their inherent usefulness. Throughout history, people discovered all sorts of ways they could make their lives more convenient. 

For instance, sporting event umpires use them to measure race times and track and field events. Athletes also use them to measure split times and personal bests. 

The medical field is another application of chronograph watches. Healthcare professionals often use them to measure patients’ heart rate. 

You also find chronographs used in traditional brewing. Brewers would set their watches to track beer-making stages, such as fermentation, to ensure chemical reactions and processes continued for the appropriate time. 

Even pilots used chronographs. Timers helped measure flight time, fuel consumption, and in-flight navigation tasks. 

Today, the use of chronographs remains widespread. Fitness enthusiasts use them to monitor the time between sets, chefs for cooking times, and scientists for chemistry and physics experiments. 

Should you get a chronograph watch?

Strictly speaking, chronograph watches are no longer necessary, thanks to modern technology. If you want to set a timer, you can always take out your smartphone and activate the stopwatch. 

With that said, chronographs are stylish, functional, and cool. Many watch-lovers prefer to use them because of their convenience. 

Chronograph watches also work better in formal settings where timing something on your phone might seem out of place. Chronographs are just as appropriate for suit-and-tie dos as they are lounging around in the park with your friends. 

The Final Verdict

Chronographs are a popular watch feature and often denote a high-end model. These clever devices might not have as many practical applications today, but they do celebrate the type of complex mechanisms watch enthusiasts love. While the technology is old, it has yet to be beaten.