This is an Arduino hydrogen gas sensor. It has high sensitivity to Hydrogen (H2) and less sensitivity to alcohol, LPG,cooking fumes . Hydrogen gas is highly flammable and will burn in air at a very wide range of concentrations
The sensitivity is able to be adjusted by the potentiometer. The output is proportional to the density of gas. You can use analog reading to read the data from this sensor.
What is Hydrogen? Hydrogen is a chemical element with chemical symbol H and atomic number 1.