Impregnated permeation tube for use in a permeation manometer is produced by impregnating a clay tube with a PTFE emulsion, followed by drying and sintering

摘要

Production of an impregnated permeation tube involves impregnating a clay tube (diameter 20 mm and length 100 mm) by vacuuming it in Dyneon TF5032 (RTM : emulsion with PTFE : water = 1 : 9), followed by drying in air for 18 hours, heating to 80[deg]C for 180 minutes, heating to 330[deg]C for 120 minutes under N2 and sintering at 330[deg]C for 30 minutes such that the PTFE closes the large pores and channels in the clay and the sintering gives a thin semi- permeable PTFE layer. An independent claim is also included for a permeation manometer having the gastight-stoppered impregnated tube slidingly positioned in a vertical mantle, the mantle having a three-way stopcock at its lower end and a sample gas inlet at its upper end, the stopcock being connected to a manometer. At the lower end of the mantle there is also a small opening for pressure equalization.