Today in this technologically advanced society we are totally surrounded by advanced sensors. With IoT the number of sensors around us would increase tremendously. Today we have a sensor for everything , name it we have a sensor. But did you try to know about the first sensor ever made?Davy lamp was the first sensor to be built ever and was made by Sir Davy in 1815 for people in mines. You should know that the word ‘sensor’ itself was first coined in 1958. So Davy lamp was invented without knowing that it will become world’s first sensor and that too before the term is coined. At that time there were no such devices which could detect poisonous gases in mines and that need lead to the invention of Davy lamp. The lamp consists of a wick lamp with the flame inside a mesh screen. The mesh screen prevents the flame to propagate through them and ignite any firedamp outside.The first sensing function Davy lamp did is that it can sense the concentration of oxygen present in the air in mines. There is a metallic scale on the lamp with which we can measure the length of the flame inside and that length itself gives an idea about the amount of oxygen present at that place. The workers can place the lamp near to ground and can test for gases like carbon dioxide which are denser than air. It can also detect various poisonous gases by various changes in flames. If at all the flame gets extinguished then it means that there is still 17% oxygen content but it is an indication telling that don’t go further into the mine otherwise you will die. So Davy lamp gives an early indication also. Even it is so old, we still use this lamp in some mines and that tells you how robust this lamp is. So that’s it guys, that was a small information about world’s first sensor.