# What is a Tachymeter ?

## What is a Tachymeter ?

Tachymeter is a bezel around the wrist watch on a clock. Tachymeter is a very accurate grading on your clock that can give the number of events happening per hour if you know how much time it takes for a single event to happen. Convesely, if you know the exact time an event takes to happen once then you can find out how many such events can happen in one hour. The tachymeter bezel is graduated in such a way that by just glancing at the tachymeter reading against the seconds needle tells you these two data. Tachymeter is an amazing piece of instrument that comes with your wrist watches and clocks. Wrist watches fitted with tachymeter costs many times a normal wrist watch. Tachymeter adds to the beauty and sophistacation of your wrist watch in addition to being higly useful to every one going about their daily routine life.

### How Tachymeter on a Clock Work?

Tachymeter works on a simple principle of t/3600. Here t is the time taken by any event to happen in seconds. 3600 is the number os seconds in one hour (60x60=3600) To give an example, you are driving your car at say 60 kmph. The time taken to cover 1 km will be 1 minute. If you are driving your car at 60 miles per hour then you take 1 minute to cover one mile. I hope that was simple enough. No consider you are driving at 95 kmph and how many seconds will it take to cover one km? Looking at the tachymeter it is very simple to find out. Just look at the figure 95 written on the tachymeter bezel and read out the seconds corresponding to it which is 38 seconds. This is how a tachymeter works.

#### Second Method to Learn How Tachymeter Work

Now consider you start your stop watch and find out that you have covered one mile in 38 seconds, then do you know your car speed if the speedometer is not working? Once again look at your tachymeter bezel and see 95 written against 38 seconds. Since you covered one mile in 38 seconds your speed as per tachymeter is 95 miles per hour. This is how tachymeter works on a wrist watch. In a glance you know your speed and distance covered. This is how tachymeter works.

##### Check Your Car Speedometer Accuracy with Tachymeter

It is possible to check the accuracy of your car speedometer by using the same principle on which the tachymeter works. Drive at a constant speed between two points exactly 1 km if your speedometer is graduated in kmph or 1 mile if it is graduated in mph. Start the stop clock when you cross the first marker and stop the clock when you cross the second market one km or one mile away. Now if the tachymeter reads the correct speed you were driving your car at. If the speed you were maintaining when doing this experiment is not same as what the tachymeter is telling you then your car speedometer is wrong and needs to be caliberated or replaced. Before you go to your car dealer see that you do this experiment a few more times at various speeds and after filling the correct air pressure in your car tyres. If the readings on the speedometer of your car and the tachymeter on your wrist watch do not match then you need to get your speedometer changed because your tachymeter is never wrong and this is how tachymeter works.

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