Nelson and Eggertsen continuous flow method

Nelson and Eggertsen/in 1958, extended the Loebenstein and Dietz technique by continuously flowing a mixture of helium and nitrogen through the powder bed. They used a hot-wire thermal conductivity detector to sense the change in effluent gas composition during adsorption and desorption, when the sample cell was immersed into and removed from the bath, respectively. 

2 is a schematic of the flow path arrangement using a four-filament thermal conductivity bridge. 

---