The global warming increasing daily and showing serious impact on earth environment due to Carbon dioxide (CO2) content in the atmosphere, and many other human activities. And it is very important to measure and analyse the concentration of Carbon dioxide before it became dangerous to humankind. In the present paper an optical signal is used to measure the level of Carbon dioxide in open space and in food Industry. So that, the engineers can take appropriate verdicts in advance before it become too late. CO2 also plays vital role as output of industrial gas, helps in production of chemicals and also in preparation of food and food packaging. The ability to quantify gas concentrations with high sensitivity, excellent selectivity and rapid response by means of direct laser absorption spectroscopy is important.