D.5 Sampling test chamber or test cell air D.5.1 GeneralEnsure that the sample tube is at approximately the same temperature as the chamber air to prevent risk of water condensation inside lhe sample tube when sampling emissions from humid samples.D.5.2 Storage of sampled tubesTubes have to be capped immediately after sampling, placed in an airtight emission-free container and stored in a clean area. Tubes packed with a single sorbent can be stored at room temperature. Sampled multi¬sorbenl tubes require storage under refrigerated conditions to minimize risk of analyte migration within the tube. Analyse tubes as soon as possible and within four weeks.Long-term storage caps on refrigerated sample tubes should be retightened once the sample has reached its minimum storage temperature.Refrigerated sample tubes should be allowed to equilibrate with room temperature before they are opened for analysis.NOTE Information on recovery of voes from sorbent tubes after storage is given in 111is part of ISO 16000 and in ISO 16017-1