RADIO CONTROLLED CLOCKS | WATCHES

The large digital wall clock in its form that we recognise today has been around since the middle of the fourteenth century. Before then, measuring the passage of time had always been a tricky affair with the movement of the sun being the only reliable method of time-telling and the only clocks being crude sundials or water clocks.

When the first mechanical clocks appeared they were driven by a spring and weight, regulated by a verge-and-foliot escapement, a type of gear system that advances the gear train at regular intervals or ‘ticks’. Not only does a clock ticking come from these original devices but also the familiar clock face was developed.

The first clock to use a minute hand appeared in 1475 and innovations like the pendulum were added making mechanical clocks more and more accurate. Shapes, designs and all sorts of bells, alarms and automaton figures were added to clocks to make them more appealing, the most famous of these being the distinctive cuckoo clock which appeared at the end of the 18th century. No large digital wall clocks back in this time period.

The next big step in the development of clocks didn’t arrive until the twentieth century and the development of electronics when it had been noticed that electrical charges running through crystals, such as quartz, made the crystals resonate at an accurate rate.

These large digital wall clocks could use the traditional clock face of mechanical clocks but also were able to replace it with a digital display that showed the time in numbers.

While large digita walll clocks were more accurate than mechanical clocks and even bigger step towards accuracy was taken with the discovery of Atomic Clocks.

Atomic Clocks work on the principle that the caesium -133 atom has an exact resonance each second (somewhere in the region of over 9 billion a second). This makes large digital wall clocks highly accurate; in fact they are even more accurate than the rotation of the Earth which the national timescale GMT (Greenwich Meantime) used to determine noon. Another timescale, UTC (universal Coordinated Time)) which is based on GMT but allows for the Earth slowing in its rotation by adding ‘leap seconds’ has been developed.

Computer networks use the time from Atomic Clocks by receiving a specialist transmission of the time through radio waves, the GPS network or over the Internet and can synchronise their networks to this UTC time by utilizing NTP (Network Time Protocol) a protocol specifically designed for synchronization.

Ethernet Clocks can be connected to computer networks that run NTP and can display the exact time as told by an atomic clock and display it on a wall or desk. Other analogue and digital wall clocks can also receive a transmission directly from an absolute time source via radio waves and display UTC time that way. Hence the large digital wall clocks that we have today.,

I like to write articles about electronics and sports

The large digital wall clock in its form that we recognise today has been around since the middle of the fourteenth century. Before then, measuring the passage of time had always been a tricky affair with the movement of the sun being the only reliable method of time-telling and the only clocks being crude sundials or water clocks.

When the first mechanical clocks appeared they were driven by a spring and weight, regulated by a verge-and-foliot escapement, a type of gear system that advances the gear train at regular intervals or ‘ticks’. Not only does a clock ticking come from these original devices but also the familiar clock face was developed.

The first clock to use a minute hand appeared in 1475 and innovations like the pendulum were added making mechanical clocks more and more accurate. Shapes, designs and all sorts of bells, alarms and automaton figures were added to clocks to make them more appealing, the most famous of these being the distinctive cuckoo clock which appeared at the end of the 18th century. No large digital wall clocks back in this time period.

The next big step in the development of clocks didn’t arrive until the twentieth century and the development of electronics when it had been noticed that electrical charges running through crystals, such as quartz, made the crystals resonate at an accurate rate.

These large digital wall clocks could use the traditional clock face of mechanical clocks but also were able to replace it with a digital display that showed the time in numbers.

While large digita walll clocks were more accurate than mechanical clocks and even bigger step towards accuracy was taken with the discovery of Atomic Clocks.

Atomic Clocks work on the principle that the caesium -133 atom has an exact resonance each second (somewhere in the region of over 9 billion a second). This makes large digital wall clocks highly accurate; in fact they are even more accurate than the rotation of the Earth which the national timescale GMT (Greenwich Meantime) used to determine noon. Another timescale, UTC (universal Coordinated Time)) which is based on GMT but allows for the Earth slowing in its rotation by adding ‘leap seconds’ has been developed.

Computer networks use the time from Atomic Clocks by receiving a specialist transmission of the time through radio waves, the GPS network or over the Internet and can synchronise their networks to this UTC time by utilizing NTP (Network Time Protocol) a protocol specifically designed for synchronization.

Ethernet Clocks can be connected to computer networks that run NTP and can display the exact time as told by an atomic clock and display it on a wall or desk. Other analogue and digital wall clocks can also receive a transmission directly from an absolute time source via radio waves and display UTC time that way. Hence the large digital wall clocks that we have today.,

I like to write articles about electronics and sports

The large digital wall clock in its form that we recognise today has been around since the middle of the fourteenth century. Before then, measuring the passage of time had always been a tricky affair with the movement of the sun being the only reliable method of time-telling and the only clocks being crude sundials or water clocks.

When the first mechanical clocks appeared they were driven by a spring and weight, regulated by a verge-and-foliot escapement, a type of gear system that advances the gear train at regular intervals or ‘ticks’. Not only does a clock ticking come from these original devices but also the familiar clock face was developed.

The first clock to use a minute hand appeared in 1475 and innovations like the pendulum were added making mechanical clocks more and more accurate. Shapes, designs and all sorts of bells, alarms and automaton figures were added to clocks to make them more appealing, the most famous of these being the distinctive cuckoo clock which appeared at the end of the 18th century. No large digital wall clocks back in this time period.

The next big step in the development of clocks didn’t arrive until the twentieth century and the development of electronics when it had been noticed that electrical charges running through crystals, such as quartz, made the crystals resonate at an accurate rate.

These large digital wall clocks could use the traditional clock face of mechanical clocks but also were able to replace it with a digital display that showed the time in numbers.

While large digita walll clocks were more accurate than mechanical clocks and even bigger step towards accuracy was taken with the discovery of Atomic Clocks.

Atomic Clocks work on the principle that the caesium -133 atom has an exact resonance each second (somewhere in the region of over 9 billion a second). This makes large digital wall clocks highly accurate; in fact they are even more accurate than the rotation of the Earth which the national timescale GMT (Greenwich Meantime) used to determine noon. Another timescale, UTC (universal Coordinated Time)) which is based on GMT but allows for the Earth slowing in its rotation by adding ‘leap seconds’ has been developed.

Computer networks use the time from Atomic Clocks by receiving a specialist transmission of the time through radio waves, the GPS network or over the Internet and can synchronise their networks to this UTC time by utilizing NTP (Network Time Protocol) a protocol specifically designed for synchronization.

Ethernet Clocks can be connected to computer networks that run NTP and can display the exact time as told by an atomic clock and display it on a wall or desk. Other analogue and digital wall clocks can also receive a transmission directly from an absolute time source via radio waves and display UTC time that way. Hence the large digital wall clocks that we have today.,

I like to write articles about electronics and sports

The large digital wall clock in its form that we recognise today has been around since the middle of the fourteenth century. Before then, measuring the passage of time had always been a tricky affair with the movement of the sun being the only reliable method of time-telling and the only clocks being crude sundials or water clocks.

When the first mechanical clocks appeared they were driven by a spring and weight, regulated by a verge-and-foliot escapement, a type of gear system that advances the gear train at regular intervals or ‘ticks’. Not only does a clock ticking come from these original devices but also the familiar clock face was developed.

The first clock to use a minute hand appeared in 1475 and innovations like the pendulum were added making mechanical clocks more and more accurate. Shapes, designs and all sorts of bells, alarms and automaton figures were added to clocks to make them more appealing, the most famous of these being the distinctive cuckoo clock which appeared at the end of the 18th century. No large digital wall clocks back in this time period.

The next big step in the development of clocks didn’t arrive until the twentieth century and the development of electronics when it had been noticed that electrical charges running through crystals, such as quartz, made the crystals resonate at an accurate rate.

These large digital wall clocks could use the traditional clock face of mechanical clocks but also were able to replace it with a digital display that showed the time in numbers.

While large digita walll clocks were more accurate than mechanical clocks and even bigger step towards accuracy was taken with the discovery of Atomic Clocks.

Atomic Clocks work on the principle that the caesium -133 atom has an exact resonance each second (somewhere in the region of over 9 billion a second). This makes large digital wall clocks highly accurate; in fact they are even more accurate than the rotation of the Earth which the national timescale GMT (Greenwich Meantime) used to determine noon. Another timescale, UTC (universal Coordinated Time)) which is based on GMT but allows for the Earth slowing in its rotation by adding ‘leap seconds’ has been developed.

Computer networks use the time from Atomic Clocks by receiving a specialist transmission of the time through radio waves, the GPS network or over the Internet and can synchronise their networks to this UTC time by utilizing NTP (Network Time Protocol) a protocol specifically designed for synchronization.

Ethernet Clocks can be connected to computer networks that run NTP and can display the exact time as told by an atomic clock and display it on a wall or desk. Other analogue and digital wall clocks can also receive a transmission directly from an absolute time source via radio waves and display UTC time that way. Hence the large digital wall clocks that we have today.,

I like to write articles about electronics and sports

The large digital wall clock in its form that we recognise today has been around since the middle of the fourteenth century. Before then, measuring the passage of time had always been a tricky affair with the movement of the sun being the only reliable method of time-telling and the only clocks being crude sundials or water clocks.

When the first mechanical clocks appeared they were driven by a spring and weight, regulated by a verge-and-foliot escapement, a type of gear system that advances the gear train at regular intervals or ‘ticks’. Not only does a clock ticking come from these original devices but also the familiar clock face was developed.

The first clock to use a minute hand appeared in 1475 and innovations like the pendulum were added making mechanical clocks more and more accurate. Shapes, designs and all sorts of bells, alarms and automaton figures were added to clocks to make them more appealing, the most famous of these being the distinctive cuckoo clock which appeared at the end of the 18th century. No large digital wall clocks back in this time period.

The next big step in the development of clocks didn’t arrive until the twentieth century and the development of electronics when it had been noticed that electrical charges running through crystals, such as quartz, made the crystals resonate at an accurate rate.

These large digital wall clocks could use the traditional clock face of mechanical clocks but also were able to replace it with a digital display that showed the time in numbers.

While large digita walll clocks were more accurate than mechanical clocks and even bigger step towards accuracy was taken with the discovery of Atomic Clocks.

Atomic Clocks work on the principle that the caesium -133 atom has an exact resonance each second (somewhere in the region of over 9 billion a second). This makes large digital wall clocks highly accurate; in fact they are even more accurate than the rotation of the Earth which the national timescale GMT (Greenwich Meantime) used to determine noon. Another timescale, UTC (universal Coordinated Time)) which is based on GMT but allows for the Earth slowing in its rotation by adding ‘leap seconds’ has been developed.

Computer networks use the time from Atomic Clocks by receiving a specialist transmission of the time through radio waves, the GPS network or over the Internet and can synchronise their networks to this UTC time by utilizing NTP (Network Time Protocol) a protocol specifically designed for synchronization.

Ethernet Clocks can be connected to computer networks that run NTP and can display the exact time as told by an atomic clock and display it on a wall or desk. Other analogue and digital wall clocks can also receive a transmission directly from an absolute time source via radio waves and display UTC time that way. Hence the large digital wall clocks that we have today.,

I like to write articles about electronics and sports

A wristwatch (relogios) or a watch is a kind of a timepiece that a person wears for referring to time. Watches first came into existence in 1600s as a modification of spring powered clocks. Modern watches have a lot of other functions like that of a calendar in addition to the display of time.

Most common type of wristwatch (relogios) is worn on person`s wrist and is tightened with help of a watchband that is made up of nylon, leather, any other plastic strap, metal link or sometimes, even ceramic. Before this, watches were pocket watches which were carried separately.

Watch designed was greatly improved in the 21st Century due to technological advances in the field of metallurgy, physical vapor deposition and composite materials. Better materials are now used for making watches which are more durable, more accurate, more aesthetic and more reliable.

Escapement is a kind of mechanism that limits and controls the unwinding in the watch. It converts a simple unwinding into a periodic energy release. This is done by gear interlocking that switches among `driven` and `free` state.

Balance wheel along with the spring or Hairspring forms a harmonic oscillator. This oscillator controls the gear system motion in the watch. This is similar to a pendulum clock.

Tourbillon is a rotating type of frame used for escapement. It cancels out the effects of the bias in timekeeping using gravity. Otherwise, the watch would have to be kept in the same position for a lot of time.

Movement in a watch is the mechanism which measures the time and hence helps to display the correct current time. The movements can be mechanical, electronic and maybe, even both. Most of the watches use electronic timekeeping these days even if the face of watch has a mechanical hand.

Watches (relogios) are mostly classified on basis of their movements. The classifications are Mechanical Movements, Tuning Fork Movement, Electronic Movement and Radio controlled movement. The source of power used can be a spring. There are Self Winding springs also present. Some modern watches off the movement of the wearer, some watches run with the help of the batteries, or electronic power. Some watches are light powered, while some of them are powered by the body heat.

Time display is generally done in the form of Analog or Digital display. Analog display is done using two hands, one each for hour and minute and sometimes another hand is used to display seconds. In digital display, usually there is a LCD screen on which the time in digital format appears.

All the watches (relogios) show the time in atleast hours and minutes. Few watches also show the date, day and some of them even have alarms. Some more complicated watches have stopwatch, lunar phases, Perpetual Calendar, Minute repeater and equation of the time.

When the sales of Swiss watch makers went down, they redesigned it and produced a much cheaper version in end of 20th Century. With the help of some graphic designers, they also launched an array of Fashionable watches. Dual time watches (relogios) for international travelers were designed. Collectable or Jewelry type watches were designed which had high miniaturization and precision along with nice aesthetic look. Some of the leading companies for this kind of watches are Papet Phillipe, Jaeger-LeCoultre, Rolex. Mass production is done by companies like Omega, Tag Heurer and Breitling.

Other type of watches (relogios) include computerized multifunction watches with electronic items like Calculators, Digital Cameras, Video Games, GPS receivers, Cellular Phones ad Keydrives were embedded in the watches. Some recent watches have also been marketed as Water Resistant as they are not as much affected by water as other watches and are categorized on the basis of their water repelling capability.

This article can also be accessed in portuguese language from the Article section of page www.polomercantil.com.br/relogios.php
Roberto Sedycias works as IT consultant for www.PoloMercantil.com.br

Measuring the passage of time has been a continual challenge to mankind. Throughout history we have created increasingly intricate devices to give us an accurate idea of the time but all of our modern methods of time keeping can all be traced back to the Sun travelling across the sky.

The first device to measure the passage of time was the Sundial, using shadows cast by a tall objects people could get an approximation of the time. The earliest Sundials historians have found are older than 6000 years. In 3500BC the Ancient Egyptians used large stone Obelisks aligned with the celestial pole as gigantic Sundials.

Technology did not move on for several thousand years, and when it did it came in the form of water. Egyptians discovered that the flow of water was regular enough to keep time and they immediately saw the advantages of water clocks over Sundials, as they could tell the time at night and in poor weather. The oldest known water clock was built at the Tomb of Amenhotep I in about 1500BC. Hundreds of years later water clocks were still in use, particularly by the Ancient Greeks who, in 400BC, used more accurate water clocks known as Clepsydras.

After the fall of the Roman Empire much of the technology behind timekeeping was lost and instead slaves were used to keep time by transferring stones, one at a time, from one helmet to another.

It was not until hundreds of years later that a French monk named Luitprand rediscovered the lost art of glass blowing in about 800AD, and because of this he is attributed as the creator of sandglasses. Legend tells of King Charlemagne possessing a huge sandglass which took twelve hours before it needed turning, with hourly divisions down its side.

Candles have also played their part in the telling of time. In 980AD King Alfred the Great used burning candles to tell the time, with markers down its side to depict times for studies, prayer, duties and rest. And from about 1000AD the Chinese used candles and ornate incense sticks to show the passage of time.

Mechanical clocks did not start appearing until about 1285AD, back then they were merely devices to let monks know when the correct time to ring the church bell was.

Although Sandglasses had been around for a few hundred years at this point it was not until about 1300AD that sandglasses became popular in Europe, particularly by sea farers from northern Italy.

The first public mechanical Clock was built into a church in Milan around 1335, it only had one hand for the hours, and it travelled clockwise to mimic the path of a sundial shadow.

Around the 1500s mechanical Clocks were slowly becoming more commonplace, however back then they were expensive cutting-edge technology compared to the simpler Sandglasses that were used throughout Europe. Churches and kitchens were often home to these classic timekeeping devices. They were even used in politics with public speeches, academic lectures and town meetings all being timed with Sandglasses. Even the House of Commons used a two minute sandglass for voting and it is rumoured the Spanish Inquisition used them for timing torture sessions.

Expense was not the only factor limiting the prevalence of mechanical Clocks, as they frequently needed maintenance and repairs. In an effort to improve this Peter Henlein from Germany invented the spring powered clock in 1510. However these clocks never kept an accurate time as they constantly slowed down, until the technology was improved by Jacob Zech of Prague who invented the Fusee or spiral pulley in 1525 which improved the clocks timekeeping.

At this point clocks still only measured the passing of hours, and it was not until 1577 that Jost Burgi invented the first clock that had a minute hand. Unfortunately the minute hand was never that accurate.

Although he never used it in a timepiece, Galileo proved in 1583, that successive swings of a pendulum always takes the same length of time, regardless of the distance the pendulum swings. It was not until Dutch astronomer Christopher Huygens used Galileos discovery of the pendulum to invent the first pendulum clock in 1656, whose minute hand was the most accurate yet.

Improvements in the Pendulum Clock lead to another leap forward in time keeping. Around 1685 the increased use of Huygens pendulum clocks allowed for timekeeping devices which can count seconds for the first time in history.

In Germany Franz Anton Ketterer uses pipes in his clocks for a two tone cuckoo noise in about 1750, and the first Cuckoo Clocks are made.

Time keeping remained the same for a while; until 1839 the Telegraph was invented, allowing the instant transmission of time signals. This, along with the increased use of Railroads, led to a big change to the measurement of time. As people were travelling rapidly in east-west directions, particularly across America, they discovered that time changed the further you travelled. Rail companies struggled to keep accurate schedules and for a while the world was thrown into a state of chaos.

In 1883 two trains collided in America because the train timetables didnt account for the change in time across different states. This disastrous event called for an immediate and critical change in time measurement. After the horrific head on train crash, the Prime Meridian conference rationalized real time over 15 degree zones, or time zones, and also set Greenwich Meridian as the starting line in 1884.

Whilst looking for more reliable ways of keeping time, Warren Marrison, a Canadian born engineer developed the worlds first quartz clock in 1927. Despite the clocks large size, Marrison proved that it was more accurate than any timepiece that had come before and Time Standard laboratories across the world abandoned their mechanical clocks in favour of quartz powered clocks.

In 1949 the International Bureau of Standards builds the first atomic clock which is so accurate it proves that the Earths orbit around the sun is slightly irregular. This led to a drastic rethinking of how time should be measured. For the first point in history the measurement of time is based on something other than the Earths orbit around the Sun. In 1967 a second is formally defined as 9,192,631,770 vibrations of a caesium atom.

Today quartz powered Clocks and Watches are everywhere, and Radio Controlled Clocks now get the correct time transmitted to them from Atomic Clocks. Clocks have become so much more than devices to tell the passage of time, with many of them being decorative centrepieces to buildings and rooms that combine function with form to produce truly striking ornaments.

There are currently hundreds of companies worldwide producing a huge range of timepieces, from wall clocks, mantel clocks, alarm clocks all the way to digital alarms and stop watches. However manufacturing methods have come a long way since the invention of the first mechanical clock, and the art of crafting ornamental clocks is getting lost. One company who still maintains this art is Newgate Clocks. Founded in 1991 Newgate has gone forward to become a world leader in decorative wall clocks and mantel clocks. Visit their website to discover why.

Newgate Clocks, the official online shop to purchase Clocks, Mantel Clocks, Alarm Clocks, Wall Clocks and Mirrors!

Time has always been a fascination for mankind although it has only been recently, thanks to the work of Albert Einstein and others, have we have begun to understand exactly what it is.

However, despite our lack of understanding, people have been preoccupied with measuring the passing of time.

Traditionally, due to concepts such as farming and religion, the measurement of time has always been based on the movement of the Earth around the Sun, understandably as the planting and growing of crops is seasonal. Also the movement of the moon has been used to measure the passing of time which has traditionally meant our calendars have been divided by the number of days the Earth goes around the Sun (365) and how long it takes the moon to circle the Earth (28).

However our calendars have always faced a fundamental problem in that the moons orbit or 28 days can be divided by seven days of a week, seven doesn’t go into 365. Furthermore the Earth takes six hours more than just 365 days to circle the sun.

This caused tremendous problems in the early days of calendars as the Roman, Julian Calendar did not  account for enough leap years and farmers soon found themselves unsure of the correct day to plant crops (as summer was slowly becoming winter and vice versa).

Fortunately the Gregorian calendar replaced the Roman calendar and the number of leap years increased to keep the seasons in line with the calendar.

The main use of calendars was to keep track of events such as harvest and religious festivals however when it came to day-to-day timekeeping accuracy didn’t start until the development of the clock in the middle-ages.

Clocks meant for the first time people could know exactly what time of day it was and would no longer have to trust observations and comparisons to measure daily time such as ‘the time it takes to walk a mile’ or ‘when the sun is at its highest. Timescales were also introduced allowing the hours in the day to be aligned with the movement of the Sun so noon would be the day’s zenith.

Following mechanical clocks, electronic clocks soon became favoured as they were far more accurate but it wasn’t until the development of Atomic Clocks in the 1950’s that true accuracy became possible.

After the atomic clock, that are accurate to within a second every million years, it was discovered that the Earth itself is not a reliable time source. The Earth slows in its axis, albeit minutely, but if nothing was done to compensate eventually in a several millennia a day would become night and vice versa.

A new timescale called UTC (Coordinated Universal Time) was developed to compensate for this, it was based on the time told by Atomic Clocks but compensated for the slowing of the Earth by adding Leap Seconds every year or so.

Atomic Clocks and UTC have meant that technologies, such as the Internet and satellite communication have now become possible. Now computers all over the world can communicate with each other using NTP servers (Network Time Protocol). NTP servers ensure the whole world uses the same timescale and means computer networks can communicate successfully all over the world.

Richard N Williams is a technical author and a specialist in the telecommunications and network time synchronisation industry helping to develop dedicated NTP products. Please visit us for more information about a network time server or other NTP server.solutions

Mankind has always been preoccupied with measuring and recording the passage of time. Timekeeping has been essential for the development of civilisations; from knowing when to plant or harvest crops to identifying important events in the year.

Time has historically been measured in relation to the movement of the Earth; a day, is one revolution of the planet; while a year is an entire orbit of the Sun. Calendars were developed from as far back as 20,000 years ago when hunter-gatherers scratched lines and gouged holes in sticks and bones to possibly count the days between phases of the moon.

Civilizations from the Ancient Egyptians to the Roman Empire have used differing methods to discover what day of the year it is. However, measuring time as it passed throughout the day had always proved difficult to early mankind. Sundials were perhaps the first time pieces and they can trace their origin back over five thousand years; when obelisks were built, possibly to allow the telling of time by the cast of their shadows.

However, the time told on a sundial was based on the movement of the sun in the sky, which would differ throughout the seasons and of course would not work on cloudy days or at night. Other methods such as water clocks or the hourglass would simply act as crude timers. Telling the time of day would prove difficult with people relying on comparisons as time references such as: “As long as it would take a man to walk a quarter mile.”

People were reliant on these methods and others such as bell ringing to indicate important moments until the 14th century, when mechanical clocks first appeared which were driven by weight and regulated by a verge-and-foliot escapement (a gear system that advancing the gear train at regular intervals or ‘ticks’). These clocks were far more reliable than sundials or other methods allowing accurate and reliable telling of the time of day for the first time in human history.

The next step forward in horology came in the 17th century when the pendulum was developed to help clocks maintain their accuracy. Clock making soon became widespread and it was not for another three hundred years that the next revolutionary step in horology would take place; with the development of electronic clocks. These were based on the movement of a vibrating crystal (usually quartz) to create an electric signal with an exact frequency.

While electronic clocks were far more accurate than mechanical clocks it wasn’t until the development of Atomic Clocks and around fifty years ago that modern technologies such as communication satellites, GPS and global computer networks became possible.

Most Atomic Clocks use the resonance of the atom caesium-133 which vibrates exactly at a frequency of 9,192,631,770 every second. Since 1967 the International System of Units (SI) has defined the second as that number of cycles from this atom which makes Atomic Clocks (sometimes called caesium oscillators) the standard for time measurements.

Atomic Clocks are accurate to less than 2 nanoseconds per day, which equates to about one second in 1.4 million years. Because of this accuracy, a universal time scale UTC (Coordinated Universal Time or Temps Universel Coordonné) has been developed that maintains a continuous and stable time scale and supports such features as leap seconds – added to compensate for the slowing of the Earth’s rotation.

However, Atomic Clocks are extremely expensive and are generally only to be found in large-scale physics laboratories. However, NTP servers (Network Time Protocol), the standard means for achieving time synchronisation on computer networks, can synchronise networks to an atomic clock by using either the Global Positioning System (GPS) network or specialist radio transmissions.

The development of Atomic Clocks, GPS and NTP time servers has been vital for modern technologies, allowing computer networks all over the world to be synchronized to UTC.

Copyright 2008 © Richard N Williams
Richard N Williams is a technical author and a specialist in the telecommunications and network time synchronisation industry helping to develop dedicated time server products; ethernet clocks, GPS time servers, NTP servers, digital wall clocks, atomic clock servers and SNTP time servers. Please visit us for more information about NTP products and NTP servers This article may be republished and reprinted in its complete form or in part without seeking permission providing a relevant link to this site is maintained. It is a violation of copyright law to reprint or publish this content without following these terms.

Atomic Clocks have been with us for over fifty years now and most people have heard of them and know they are very accurate, but how accurate are they and why do we need such accurate clocks?

Atomic Clocks are used by many of us even if we are not aware of it. The time they tell is relayed around the world and picked up by time servers using the protocol NTP to synchronise networks, they are vital for lots of technologies, such as global satellite navigation, and TV signal timings.

Before the development of the atomic clock the most precise timekeeping devices were electronic clocks which would lose a second or two every week. These had largely replaced mechanical clocks which were less accurate still.

Mankind has always had a fascination for keeping track of the time but knowing the precise time has never been too important. A second or even a minute’s difference does not affect our day-to-day lives.

However, as technology has advanced the need for more precise timekeeping has increased. Satellites that have to be navigated and communicate with the Earth from hundred, thousands and even millions of miles away require exact timing. Light and therefore radio waves can travel 300,000 km every second so slight inaccuracies in time can have massive differences.

The first accurate atomic clock was built y Britain’s National Physical Laboratory in 1955 by Dr Louis Essen who based his clock around the oscillation of the caesium -133 atom. The idea was actually first conceived as far back as 1879 when Lord Kelvin proposed that time-keeping based on how atoms behaved would be a better way to count time intervals than anything else.

The first generation of Atomic Clocks (also known as caesium oscillators) used the frequency of this atom which oscillates 9,192,631,770 times every second. Essen’s model was accurate to a second every 300 years but developments of the caesium oscillator mean they can now achieve accuracies of one second every 80 million years.

Yet as technologies get more advanced, scientists strive to make better and more accurate clocks. Rubidium standard clocks offer no better accuracy than caesium models but are smaller and cost less (caesium oscillators are generally only to be found in large-scale physics laboratories).

Clocks using just a single atom have been developed that offer even more accuracy. A clock based on a single mercury atom has achieved accuracies of one second in 400 million years and it is expected that a new type of strontium clock that uses light will go even better.

The future for Atomic Clocks is ever increasing accuracy combined with scaling down the size and cost of them. The American National Institute of Standards and Technology (NIST) have unveiled a chip-sized atomic clock that boasts millisecond accuracy.

Atomic Clocks are now part and parcel of our lives without the time signals they transmit to the world that are picked up by NTP servers modern communication from Internet shopping and GPS and technological advances such as satellite navigation would become impossible.

Richard N Williams is a technical author and specialist in Atomic Clocks, telecommunications, NTP and network time synchronisation helping to develop dedicated NTP clocks. Please visit us for more information about atomic clocks or other network time server solutions.