Measurements of the electric field and of the voltages of very short arc high-pressure sodium discharges (arc tube internal diameter 7.4 mm) have been used to estimate the electrode fall in high-pressure sodium lamps. These data are needed for the design of new ratings of high-pressure sodium lamp. Two methods have been used to avoid the systematic errors in field which result from depletion of the amalgam of sodium at high liquid amalgam temperatures. The electrode voltage fall is approximately independent of electrode construction for emitter coated electrodes at 4 ± 1 V. For pure tungsten electrodes it is 8 ± 1 V. The electrode fall is independent of discharge currents within the range 1-4.45 A.
Get full access to this article
View all access options for this article.
References
1.
de Groot, J.J., Investigation of the high pressure sodium and mercury/tin iodide arc, doctoral thesis, Technische Hogeschool, Eindhoven (1974).
2.
Ecker, G., Electrode components of the arc discharge, Ergebnisse der Exakten Naturwissenschaften, 33, Springer (1961).
3.
Jack, A.G., and Koedam, M., J. Illum. Engng Soc., 3,323-329 (1974).
4.
Jack, A.G., High pressure gas discharges at intense non -coherent light sources, Proc. 10th international conference on phenomena in ionized gases , Oxford, invited papers volume, 205-229 (1971).
