States the methods of test to be used for determining the characteristics of low pressure sodium vapour lamps of the integral type, both U-shaped and linear, operating on a.c. mains, 50 Hz or 60 Hz.
States the methods of test to be used for determining the characteristics of low pressure sodium vapour lamps of the integral type, both U-shaped and linear, operating on a.c. mains, 50 Hz or 60 Hz.