The Michell Instruments PSD2 and PSD4 Pressure Swing Dryers use two columns filled with 4Å molecular sieve desiccant, which are used alternately on a switching cycle. Designed for continuous operation, these dryers use a small proportion of the dried air to regenerate the offline column, typically providing desiccant life in excess of five years. This heatless regeneration method consumes significantly less energy than heated dryer systems.

PSD2 Dryer: Fitted with inlet and outlet pressure regulation, this model delivers up to 7 Nl/min (14.8 scfh) of dry air with a moisture content of 1 ppmV or better. It features a mechanical cam timer for reliable switching cycle control.

PSD4 Dryer: Featuring stainless steel internal components and larger volume desiccant columns, the PSD4 delivers exceptional purity. Combined with high-integrity VCR couplings, the standard and HPO versions provide output up to 30 Nl/min (63.6 scfh) with moisture content better than 14 ppbV. The HFV version delivers up to 90 Nl/min (109.7 scfh). A programmable relay timer provides flexible cycle control.

Both models offer excellent long-term stability with completely maintenance-free operation except for desiccant replacement once every five years. They are completely self-contained with low power consumption and standard IEC power sockets, making them ideal for providing ultra-dry reference gas for calibration systems, analytical instrumentation, and applications requiring extremely low moisture content carrier gas.