Altimeter is a special type of aneroid barometer, used in measuring altitudes.
![](https://syskool.com/wp-content/uploads/2013/11/images-1.jpg)
Ammeter is an instrument to measure the strength of an electric current.
![](https://syskool.com/wp-content/uploads/2013/11/Moving-Iron-SR-80-A-C-Acrylic-Ammeter.jpg)
Amplifier is an electronic device that increases the strength of a signal fed into it.
![](https://syskool.com/wp-content/uploads/2013/11/Karaoke-Power-Amplifier-MV-2500.jpg)
Anemometer is an instrument to measure the velocity and find the direction of the wind.
![](https://syskool.com/wp-content/uploads/2013/11/anemom-bertiel.jpg)
Audiometer is an instrument to measure difference in hearing.
![](https://syskool.com/wp-content/uploads/2013/11/audiometer.jpg)