摘要 |
An electric arc discharge lamp comprises an arc discharge light source (12) emitting both visible and UV radiation enclosed within a borosilicate glass envelope (14) having a transmission exceeding 90% at 425 nm, not more than 40% at 325 nm, 8% at 300 nm and 0.5% at 290 nm. The glass comprises the following oxides in wt.%: Na 3.89, K 1.5, Li 0-0.15, pref. 0.15, B 17, Al 1.4, Ca 0.6, Mg 0.35, Fe 0.13 and the balance silica. |