The gas diffusion chamber can determine the permeability of different plastic films for modified atmosphere packaging and transport. This was made from cold-rolled steel with an outer diameter of 10 cm, inner volume of 140 ml and 6 cm diameter opening. Using exponential decay technology combined with gas chromatography, researchers can determine the transmission rate of oxygen (O2) and carbon dioxide (CO2) through the observed film. Information derived from the device helps people select the proper plastic film (in terms of material and thickness) to maximize the benefits of modified atmosphere storage.