Quartz clock

Quartz clocks and quartz watches are special kinds of timepieces that use a tiny piece of quartz crystal to keep very accurate time. Inside these clocks, an electronic part called an oscillator is controlled by the vibrations of the quartz crystal. These vibrations happen at a very steady rate, which helps the clock keep perfect time.

Because of this clever use of quartz, quartz clocks are much more accurate than older mechanical clocks. They can tell time much better, often being at least ten times more precise.

When digital electronics became popular in the 1980s, making these clocks smaller and cheaper, quartz timekeepers became the most common way people keep track of time. Today, you’ll find them not just in wall clocks and wristwatches, but also in computers and many other devices that need to know the time.

Explanation

Quartz clocks and watches use a special crystal called quartz to keep time. When electricity passes through quartz, it vibrates at a very steady rate. This helps the clock stay very accurate, much better than older mechanical clocks.

Inside the clock, a tiny piece of quartz shakes back and forth many times each second. This shaking creates a signal that the clock uses to count seconds, minutes, and hours. Most quartz clocks shake the quartz 32,768 times each second. This number is special because it is a power of two, which makes it easy for the clock’s electronics to count time. This helps the clock keep good time even when the temperature changes.

Mechanism

Quartz clocks use a tiny piece of quartz that shakes back and forth very quickly. This shaking happens exactly 32,768 times every second, which is a special number because it is a power of two. This helps the clock keep very accurate time. The quartz piece is usually shaped like a small tuning fork and is very small, about the size of a few millimeters. Because of this precise shaking, quartz clocks are much more accurate than older mechanical clocks.

Accuracy

Quartz clocks and watches are very good at keeping time because they use a special piece of quartz that vibrates in a steady way. This helps them stay more accurate than older mechanical clocks. A good quartz watch or clock might only be off by about 15 seconds over 30 days, which means it could lose or gain less than half a second each day.

Temperature can affect how well a quartz clock keeps time, but designers have smart ways to handle this. Watches are often made to work best when worn on a person’s wrist, using body heat to stay steady. Some very accurate clocks can keep time within just a few seconds all year. Special designs and tools help make sure these clocks stay precise, even when the temperature changes a lot.

Quartz crystal aging

Quartz crystals used in clocks are made in very clean places and kept safe in special sealed containers. Even so, the time kept by these crystals can change a little bit over time. This change, called aging, is usually smaller than changes caused by temperature but can still happen.

Things like stress, losing the seal on the container, or getting dirty can make the crystal’s time change a bit. Most of these changes happen in the first year the crystal is used, and then they slow down. Some crystals can be treated with heat before they are put in clocks to make them age faster, so experts can plan for any changes. This helps keep the clock more accurate for longer. Better clocks often use crystals that have been treated this way to make sure they stay precise.

Chronometers

Quartz chronometers used as precise time standards often have a special crystal oven to keep the crystal at a steady temperature. Some can check themselves and use "crystal farms" to find the best average time from several measurements.

External magnetic interference

Analog quartz clocks use special motors that are controlled by a magnetic field. These motors can be disturbed by strong magnets nearby, which might make the clock hands stop, move too fast, or even go backward. Moving the clock away from the magnet usually fixes the problem.

Digital quartz clocks are not affected by everyday magnets because they do not use these kinds of motors. However, very strong magnets, like those found in MRI machines, can damage quartz clock movements.

History

The properties of quartz were discovered in 1880. In 1921, the first quartz crystal oscillator was built. In 1927, the first quartz clock was created, using a quartz crystal to keep very accurate time.

During the 1930s and 1940s, quartz clocks were used in labs for very exact time measurements. In the 1960s, the first quartz watches were made. These watches were very expensive at first, but as technology improved, they became cheaper and more common. By the 1980s, quartz clocks and watches were used in many everyday items like kitchen timers, alarm clocks, and even watches. Today, quartz timepieces are very accurate and do not need much care because they have very few moving parts.

Early quartz clocks for consumers

First European quartz clock for consumers "Astrochron", Junghans, Schramberg, 1967

First quartz wristwatch movement, Caliber 35A, Seiko, Japan, 1969