Abstract :
The illumination from a finite linear light source is calculated, first for a perfectly diffusing source, then for a source which approximates closely the light distribution from a real fluorescent lamp. After treating the most general case, convenient expressions for some special conditions are obtained by means of series-expansions. The relation between total flux and normal intensity, the effect of reflectors and the results of experimental checks are discussed subsequently. Derivations and a discussion of corrections for end effects, experimental procedure, etc., are given in six appendices.