Versatile, four-port surface area and pore size analyzer. Operates in both patented helium-free and classical modes, even at the same time on different ports! Sample independence assured by individual transducers and coolant baths, unique analysis types and even different start-times. Optional very low area (krypton) capabilities possible by virtue of patented high-vacuum turbo pump and precision low-pressure transducer. External roughling pump supplied separately.