Original CPC Box schematic dP 3-way Leak check valve CPC flow 1 lpm CPC rotameter CPC +drier flow 5-9 lpm f mfm Nafion drier Drier flow 4-8 lpm manifold co rotameter f mfm To pump co Critical orifice f Filter The following photos show different versions of the CN box. mfm Mass flow meter dP Pressure gauge

Version 1: Oldest design Version 1: Oldest design. Direction of flow for sample (red) and sheath (yellow) air is shown. Exhaust manifold CPC inlet flow CPC MFM filter Drier MFM filter CPC Sample MFM CPC exhaust Counterflow Nafion drier CPC CPC Drier MFM Critical orifice for drier flow Vacuum gauge Sheath Rotameter Sample Rotameter

Version 2: More recent. Replaced Brooks MFMs with TSI MFMs (serial output).

Version 3: Most recent. Removed vestiges of drain bottle tubing loop.