Luminous efficiency meter for electric arcs

Abstract

An instrument for on-line measurement of luminous output and luminous efficiency of a vortex-stabilised argon arc lamp has been constructed. Input power to the lamp is measured with a Hall-effect multiplier and the luminous output is measured with a visually corrected selenium cell. A commercial analogue dividing unit provides a quotient signal that is proportional to the luminous efficiency of the lamp. Two ranges of 10 and 50 lumens/watt are available in the one instrument.