Bayard

Fig. 14. Ionisation gauges (a) triode head and (b) Bayard-Alpert.

The discovery of the x-ray effect spurred the development of a new generation of hot-cathode gauges designed to minimise this effect. One of the earhest, and commercially the most successful, the Bayard-Alpert gauge shown in Eigure 14b, was developed in 1950 (13). A fine wire, the ion collector, is... 

In practice, it is often necessary to take readings from hot-filament ionization gauges or other devices. Figure 5 gives pump-down curves for six different types of pumping equipment on the same vacuum chamber (23). The shape of curve 1 indicates that a real leak could be responsible for the zero slope demonstrated by the Bayard-Alpert gauge (BAG). The shape of the other curves could result from a combination of real and virtual leaks. 

Fig. 5. Plots of pump-down performance for pumps operating on 0.1-m-dia x 0.43-m-long stainless-steel tubing. Curves 1—4 are sputter-ion pumps of different makes curve 5 is Orbitron type and curve 6, LN-trapped oil DP. Pressure is measured using Bayard-Alpert gauge (BAG) (26). To convert Pa to...

Fig. 6. Bayard-Alpert gauge response vs time upon cutting off power to Orbitron pump (27). To convert Pa to torr, divide by 133.3.

Fig. 13. The introduction of a modulator electrode in a Bayard-Alpert gauge permits the pressure range to be lowered by a factor of 10 to 133 pPa...

Information available regarding the chemistry of lead in air is limited. Before the ban on sales of leaded gasoline, lead particles were emitted to the atmosphere from automobiles as lead halides (mostly PbBrCl) and as double salts with ammonium halides (e.g., 2PbBrCl NH4Cl. Pb3[P04]2, and PbS04 [Biggins and Harrison 1979 Ter Haar and Bayard 1971]). After 18 hours, approximately 75% of the bromine and 30-40% of the chlorine disappeared, and lead carbonates, oxycarbonates and oxides were produced. 

TerHaarGL, Bayard MA. 1971. Composition of airborne lead particles. Nature 232 553-554. 

Vor Erfindung der BAYARD-ALPERT-Rohre hat Apker 1948 (2) den Versuch untemommen, aus der fur den Aufbau einer Monolage erforder-lichen Zeit ein MaB fiir den im Versuchsraum herrschenden Druck zu gewinnen. 

L. Ghosez, B. Serckx-Poncin, M. Rivera, P. Bayard, F. Sainte, A. Demou-lin, A. M. Frisque-Hesbain,... 

Fig. 1.31. Scheme of ion gages (a) conventional ion gage (b) inverted ion gage (Bayard-Allpert gage). 

Bayard, R., Bama, L., Mahjoub, B., Gourdon, R. (1998) Investigation of naphthalene sorption in soils and soil fractions using batch and column assays. Environ. Toxicol. Chem. 17, 2383-2390. 

M Barbacanne, J Souchard, B Darblade, J Iliou, F Nepveu, B Pipy, F Bayard, J-F Arnal. Free Radic Biol Med 29 388-396, 2000. 

Mesange F, Sebbar M, Capdevielle J, Guillemot JC, Ferrara P, Bayard F, Poirot M, Faye JC (2002) Identification of two tamoxifen target proteins by photolabeling with 4-(2-morpholinoethoxy)benzophenone. Bioconjug Chem 13(4) 766-772... 

Elhage R, Arnal JF, Pieraggi MT, Duverger N, Fievet C, Faye JC, Bayard F (1997) 17 beta-estradiol prevents fatty streak formation in apolipoprotein E-deficient mice. Arterioscler Thromb Vase Biol 17 2679-2684... 

Bayard, C., Holmquist, L. and Vesterberg, O. (1996) Purification and identification of allergenic alpha (2u)-globulin species of rat urine. Biochim. Biophys. Acta 1290, 129-34. 

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