・ This tube is filled with two layers of 20-40 mesh carbon beads (sorbent), the front layer weighing 400 mg, and the back layer weighing 200 mg.
・ It is filled with more carbon beads than the standard model, so it is particularly suitable for sampling gas from strongly volatile organic compounds, and can also be used for long sampling times in high concentration environments.
・ Since there are two layers, the amount of breakthrough during measurement can be determined.