The colorimetric tubes were one of the first techniques that allowed to quantify the concentration of a gas or vapor in the environment by means of a "direct" reading method, they are a low cost tool that allows to have a semi-quantitative result of the concentration of a compound in the air by specific chemical reactions for each compound that generate a distinctive color indicating the value or range in which the concentration is found and giving information to make more in-depth decisions such as monitoring in real time or by sampling using a pump suction.
