Quartz Clocks


By Aanchal Mahajan

I, for one, am obsessed with watches. The wristwatch ticking on my left wrist, well, has always been a source of fascination for me.  Before I start with anything else, this article is like a slight continuation to the one on pendulum clocks in the last issue. So if you get stuck with some terms, feel free to enter “Pendulum Clocks” in the search tab.

Quartz clocks are the most commonly used timekeeping devices of the day, as they are quite accurate and suitable for daily use, and at the same time, are cheaper than the extremely accurate atomic clocks. The most important and apparent advantage of these clocks over pendulum clocks is the fact that they don’t need to be winded up regularly. Pendulums may have the same time period regardless of drag however, they will eventually have to stop. Thus, a spring is winded up to provide the swinging pendulum with enough energy to sustain its swing for a longer time period. Yet, this is also not enough, and this is why these clocks had to be regularly winded, which unfortunately, people kept on forgetting. Quartz clocks provided a welcome solution to this problem. 

Quartz clocks consist of a quartz crystal that is piezoelectric, i.e., it not only generates a small electric current on being squeezed but also vibrates at a precise frequency when an electric current passes through it. A small battery in the watch, which doesn’t need to be winded everyday but only replaced once in a while, provides this electric current, making the quartz crystal vibrate at a frequency of 32768 times per second. The electronic circuit in the watch keeps track of the vibrations generates an electric pulse per second that rotates the gears of the clock, ensuring accurate timekeeping. 

However, nothing is perfect, and since atomic clocks are undeniably more accurate than quartz clocks, one tends to question, “So why are they not 100% accurate?” The reason is that the frequency of the vibration of the quartz crystal is also affected by changes in the surrounding temperature and pressure conditions. As a result, a watch constantly on your wrist is more likely to be a better timekeeper than the one you keep on taking off and putting on. This is because our body temperatures are constant, however, they can be different from temperature of our environment. Thus, while the watch on the wrist will be subjected to almost constant temperatures, the other one will be subjected to different temperatures, leading to inaccuracies. Not just that, imperfections in the circuit and gearing, along with friction, lead to errors in the timekeeping. However, the maximum error is only the gain or loss of a second a day, which can be easily be corrected by the loss or gain of another second the other day, leading to an overall error of a second in a couple of months. This, of course, is quite accurate, and the cheapness of these watches has paved their way to becoming the most popular timekeepers today.