What type of tubing connects a SAMM to the sample area?

• A. The network module
• B. Rigid metal tubing
• C. Semi-rigid Polyethylene Tubing (Freeways)
• D. Rigid PVC tubing

Answer: (D)

Keep the sample path clean and the flow stable by using tubing that won’t react with the sample, won’t shed contaminants, and won’t kink or flex in a way that changes flow. Rigid PVC tubing fits this need well. It’s chemically resistant to a wide range of gases and refrigerants, so it won’t react with or contaminate the sample. Its rigidity helps maintain a straight, predictable flow path, reducing the risk of kinks, leaks, or dead volume that can alter readings. It’s also easy to clean and disinfect and works well with standard SAMM fittings, making maintenance straightforward.

In contrast, the other options don’t offer the same combination of chemical compatibility and mechanical stability. A network module isn’t tubing at all, so it can’t serve as the conduit for the sample. Rigid metal tubing can be prone to corrosion or surface reactivity with some gases and is heavier and harder to handle. Semi-rigid polyethylene tubing is flexible and more likely to kink, sag, or introduce variable flow, which can compromise sample integrity and measurements.