Pressure Reversals 



187 



A FURTHER STUDY OF PRESSURE REVERSALS IN THE 

 CORONA DISCHARGE. 



F. O. Anderegg, Purdue University. 



Last year K. B. McEachron presented a paper before this Academy, 

 entitled, "Some Characteristics of a Siemens Ozonizer," ' in which a 

 number of experiments with a corona discharge in stagnant air were 

 described. Some very peculiar results were obtained which are not 

 well understood. Further work seemed desirable and an account is given 

 here of some experiments which have been made under somewhat dif- 



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77/ne //7/y/n. 



Fig. 1. There if usually an initial jumi) in the pressure on turninu' on the dis- 

 charge due to the ionization pressure (Kunz). At C there is a leveisal in piessure 

 which is rather abrupt. When the current is turned off at B there is a sudden decrease 

 in pressure due to the removal of the forces which produce the ionization piessure. 



ferent experimental conditions. New facts are added tc our knowledge 

 of reversals and the foundation is being laid for an adequate explana- 

 tion of these peculiar effects. It seems almost certain that the effects 

 are catalytic in nature but the mechanism needs further ehicidation. 

 Experi)nental : A No. 36 aluminum wire was placed at the axis 

 of a Liebig condenser and was surrounded by four glass rods each two 

 mm. in diameter. From the dielectric constant of the glass it is pos- 

 sible to calculate their dielectric effect on the discharge (Cf. preceding- 

 article). Air, dried and freed from carbon dioxide, was enclosed within 

 the tube and the discharge was allowed to pass under definite condi- 

 tions. The method of making analysis of the gases for ozone and oxides 

 of nitrogen has been described." A small transformer was used to step 



' McEachron. Proc. Ind. Acad. Sci. 1021, p. 171. 

 - Anderegg, Proc. Ind. Acad. Sci. 1921, p. 159. 



"Proc. 38th Meeting-, 1922 (1923)." 



