Why does my watch get about 20 seconds faster every week?

the title is prety much self-explanatory. my watch was set to the school bell, but it gets 20 seconds faster every week. i know the bell stays consistent because several people said it is. i told my mom about this, and she said my grandpa’s watches could never keep time right either. what’s up with this?

What do you expect from a $3 watch?

grandpa’s watches? 20 seconds a week would not be bad at all for a mechanical wristwatch.

In any case, much more important than running fast or slow is that it run at a constant rate. I have kept track of many watches (celestial navigation requires you know the time to the second) and it never bothered me if they were fast or slow as long as the rate was constant as you can easily apply the required correction. A watch which runs fast or slow at a constant rate is much better than a watch which runs unpredictably fast or slow.

I’ve never considered school timepieces to be accurate myself, but even in the digital age, watches aren’t exact. I’ve had a mid-range Timex digital watch for… many many years, and as sailor sez, I know from experience it loses exactly 3 seconds a week, and I can easily account for that. My brother’s 400$ watch probably keeps better time, but I"m not willing to spend that much for the precision.

hmm… how did you know how much my watch cost? actually, it was $4.99. but my sister had said something about the watch picking up electricity from it owner. is this true?

Don’t let your sister buy the Inquirer anymore. There is another thread on watches and effects of people on them.

Even a cheap quartz watch should do better than yours. Decent quartz watches ($50 and up) should be within 1 minute a year although the guarantee is usually more like 5 minutes a year.

My current Seiko and Bulova are both in the “couple of seconds a month” range of accuracy.

You just have a cheap quartz watch that is calibrated reasonably well for the low price. Try laying it on your dresser for a few weeks and see if it still gains the same amount of time.

Snap the back off, maybe there is a trimmer to adjust the speed.

The only thing it picks up from you is heat and that does affect it. Temperature changes affect the rate at which the quartz oscillates. If you keep track of the rates of quartz timepieces you will notice the rate tends to change and stabilize with time. At least that is my experience.

You can get lucky with a cheap quartz watch but most of them use cheap quartz crystals which will not give the same precission or stability that a better quartz will give. If you want precision, get yourself a better timepiece, let it age and stabilise and then keep it in a temperature controlled setting. That should give you fairly good results.

And, BTW, your computer’s clock is a cheap quartz oscillator. My experience is that they are pretty awful. The computer I am using right now probably gains about a minute a month (although I no longer keep track of the rate of every time piece as I used to).

If you are going to keep precise track of the rates of timepieces you need to keep track of the leap seconds introduced or subtracted by the USNO at the end of the year or semester. If you forget to account for that it will drive you crazy as the pieces seems to gain or lose a second out of nowhere.

Which means that the watch will run at different rates depending on whether you’re wearing it or it’s sitting on the nightstand.

I got to see a demonstration of this a while back. An acquaintance did the following:

Someone was wearing a quartz watch with an analog display and a second hand, which is run be a stepper motor. He put it on an RF/microwave pickup device (originally designed to “sniff” for leakage from ovens) which could detect the stepper motor moving the second hand. He compared the ticks from the to the 1 pps output from an HP5071 cesium clock*.

You could see the frequency change over the ~20 minutes of data as the watch cooled off.

*there are private citizens who own atomic clocks. click here

I love it! Mommeee!! I want a cesium beam standard too!!! I couldn’t find a price for it on the Agilent web site. If you have to ask . . .