Big Chemical Encyclopedia

Chemical substances, components, reactions, process design ...

Articles Figures Tables About

Single pumps, vacuum producing

A static mass spectrometer only has a single inlet and no changeover valve. The required 8 value is obtained by comparing the ion beam intensities of the unknown sample with aliquots of a reference gas admitted to the instrument before and after the sample. Since it is essential to pump the mass spectrometer to high vacuum ( 10 °Torr) after each analysis, the total time required to produce one 8 value is 30 min. Notwithstanding any instabilities that may operate over this timescale, precisions in and d N of +0.5%o can be obtained routinely... [Pg.2890]

Figure 10.8 Comparison of CO2 produced during TAP vacuum pump-probe experiments and atmospheric flow experiments for CO oxidation over single Pt particle with the same composition of reactants, (a) A typical set of pump-probe CO2 responses (m/e = 44) for reaction at 140, 170, and 350 C. There is a shift in the amount of CO2 produced during both CO and oxygen pulses as temperature increases, (b) CO2 production observed from atmospheric flow experiment. The CO2 produced while increasing reactor temperature is less than the CO2 produced during reactor temperature decrease as shown by the counterclockwise hysteresis loop, (c) CO2 production observed from vacuum pump-probe experiment The black line represents the total CO2 yield. The circle and diamond points represent the CO2 yield on the oxygen pulse and CO pulse, respectively. Figure 10.8 Comparison of CO2 produced during TAP vacuum pump-probe experiments and atmospheric flow experiments for CO oxidation over single Pt particle with the same composition of reactants, (a) A typical set of pump-probe CO2 responses (m/e = 44) for reaction at 140, 170, and 350 C. There is a shift in the amount of CO2 produced during both CO and oxygen pulses as temperature increases, (b) CO2 production observed from atmospheric flow experiment. The CO2 produced while increasing reactor temperature is less than the CO2 produced during reactor temperature decrease as shown by the counterclockwise hysteresis loop, (c) CO2 production observed from vacuum pump-probe experiment The black line represents the total CO2 yield. The circle and diamond points represent the CO2 yield on the oxygen pulse and CO pulse, respectively.
See other pages where Single pumps, vacuum producing is mentioned: [Pg.191]    [Pg.1698]    [Pg.33]    [Pg.140]    [Pg.196]    [Pg.433]    [Pg.482]    [Pg.20]    [Pg.8]    [Pg.22]    [Pg.9]    [Pg.192]    [Pg.192]    [Pg.41]    [Pg.192]    [Pg.35]    [Pg.433]    [Pg.53]    [Pg.199]    [Pg.161]    [Pg.81]    [Pg.837]    [Pg.104]    [Pg.246]    [Pg.291]    [Pg.93]    [Pg.78]    [Pg.176]    [Pg.40]    [Pg.187]    [Pg.661]    [Pg.762]    [Pg.387]   
See also in sourсe #XX -- [ Pg.365 ]



SEARCH



Vacuum pumps

© 2024 chempedia.info