For condensation prevention in sampling, Vaisala recommends using a Nafion membrane tube to maximize transfer of water vapor from the sample to ambient air. The Nafion material is highly selective in the removal of water. Water moves through the membrane wall and evaporates into the surrounding air in a process called pervaporation. For more information about the technology, see permapure.com.
The following accessories for tube sampling are available, either when ordering the GMP80P probe or from store.vaisala.com:
| Description | Item code |
|---|---|
| Sampling tube (Nafion membrane and polyurethane), 2.1 m (6 ft 11 in) 1 | GMTUBESP |
| Sampling tube (Nafion membrane), 0.6 m (1 ft 12 in) | 212807SP |
| Sampling tube (polyurethane), 1.5 m (4 ft 11 in) | 279471SP |
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To prevent breaking the Nafion tube, do not insert it directly through the incubator sampling port or attach it to GMP80P. Instead, use a short section of plastic tube (for example, polyurethane tube) at both ends of the Nafion tube. For a setup example, see CO2 sampling from incubator using tube, with GMP80P connected to Indigo80.
Plastic tube specifications:
Vaisala spare part item GMTUBESP consists of a Nafion tube and a compatible polyurethane tube for this purpose. |