The PD1T-1.5 is a low-flow sample dryer often used at the inlets of trace-gas analyzer systems in a profile or multi-site gradient application. A configuration of having a dryer at each intake may be needed at sites where condensation is likely. The dryer removes water vapor from the air sample before entering the analyzer, thereby limiting measurement interference and eliminating the need for corrections to the trace-gas flux due to water vapor flux (i.e., eliminates the need for the WPL correction). The PD1T-1.5 consists of a 1.5 ft Nafion® dryer element manufactured by Perma Pure, Inc., that is housed in a rugged dryer shell designed and manufactured by Campbell Scientific. The PD1T-1.5 does not include an intake filter, needle valve, or flow meter. The purge connections on the PD1T-1.5 are 3/8 in. Swageloks, and the sample inlet and outlet connections are 1/8 in. SS tubes.