Suppose I have a leaked gas from a pipe. With a laser spectrometer I can measure the concentration of a gas (methane) in the leaked air. Can I predict the concentration of the gas (methane) inside the pipe (ppm)?
Yes, diffusion factor of gases can be measured using various methods. Common method is to conduct a diffusion experiment using a setup known as a diffusion cell. In this, a known concentration of gas introduced into one side of a cell, while the other side remains at a lower concentration or empty. Diffusion of the gas through the cell is measured over time using various instruments such as gas chromatography or mass spectrometry. By analyzing the change in concentration over time, the diffusion factor can be determined.