MEASUREMENTS OF PARTIAL OUTGASSING RATES

To investigate the surface composition and outgassing rates of a serie s of samples, the size of these should be small and the measuring time variable. Because the species of desorbed gases vary with dependence on time and temperature, the outgassing measurements using total press ure gauges include some errors caused by the conductance and the gas c orrection factor for the gauges. To reduce these errors we developed a n outgassing measurement system on the basis of a modified throughput method with quadrupole mass spectrometers. By this method it is possib le to measure partial outgassing rates. The change of major gas compon ents is discussed. Some examples of the outgassing behaviour of stainl ess steel, nickel and chromium coated brass are given.