# Decoding An Aircraft Tachometer!

Aircraft have always remained an elusive subject for us. We all are intrigued about the way an aircraft functions and are often eager to know more about them. Aircraft Tachometer is one such subject that comes across as a mystery. Here we will try to decode the same for a layman’s understanding. Firstly, it is important to understand that what exactly is meant by this device. Well, just as the speedometer is for measuring the speed of a car, a tachometer also helps to gauge the speed of a moving object. The only difference being, that in the case of a tachometer the speed is calculated by measuring the rotation or revolution of the machine. These devices come in the shape of small dials with a needle inside them that point at the prevailing speed level as per the revolutions per minute. Thanks to technology, a lot of people are also using the digitized form of tachometers today.

### Older Version Of Tachometer

The earlier version of the tachometer is still widely used across the globe. A dial is a circular object like a compass that has a needle, which will simply point at the prevailing level of revolutions taken by the moving object per minute. The whole objective of this device is to ascertain just how hard the aircraft engine is working. The engine revolutions are calculated electrically from the coil in the engine.

There are many engines that have an ignition system in place. In such a case, a small generator is fixed to the shaft of the engine. The Aircraft tachometer functions like a voltage meter in such a case. In a way, you can say that it counts the pulse or revolution of the ignition system. The voltage output is related to the speed so it gives an accurate rate of RPMs. The voltage taken into consideration is actually from a permanent magnet that is placed on the shaft.

The aircraft tachometer is known to gauge the frequency from the change in engine coils’ direction. Similarly, once the engine is functioning too quickly a higher voltage will be emitted that will be caught in the tachometer.

### Sparks: The New Method

This is a relatively new mode of the tachometer. In this case, the speed is determined on the basis of the sparks emitted by the aircraft engine. This is only applicable in the case of a petrol engine where spark plugs are used to derive energy to move the vehicle.

### Laser Technology

With the advent of technology, a lot of aircraft are opting for the laser option. These laser aircraft tachometers are simple to use and accurate too. In the laser technology, unlike the other versions, the tachometer does not need to be connected to the aircraft engine. It beams infrared light on the engine shaft and the speed is calculated on the basis of the light emitted back. Many new age aircraft are using it for their convenience as the laser ones have an edge over the older versions.

Hope we could decode the aircraft tachometers for your understanding! It’s time to experiment now!

One clap, two clap, three clap, forty?

By clapping more or less, you can signal to us which stories really stand out.