HIGH-PRESSURE SODIUM VAPOUR DISCHARGE LAMP INCLUDING XENON

摘要

The invention relates to a high-pressure sodium vapour discharge lamp comprising a discharge tube containing sodium and xenon. In accordance with the invention the inside diameter of the discharge, tube is below 5 mm and greater than 1 mm. In addition the xenon pressure is relatively high in the operating condition of the lamp which - together with a pressure of the sodium in a given range can result in a high luminous efficacy of the lamp.