Extra High Pressure Mercury (Vapour) Lamp

2-3-375

A mercury vapour lamp in which, during operation, the partial pressure of the vapour reaches a very high value, of the order of 106 newtons per square metre (10 atmospheres) or more.

Reference: C.I.E.

Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)

English