Fluorescent-lamp photometry (determination of flux from illumination measurements at short distances)

Methods are proposed for determining the flux of a fluorescent lamp from illumination readings at a comparatively close distance without the aid of an integrator. A full mathematical analysis based on a previous paper of the authors is given and experimental checks are described. Of the methods described, one, the ¿three illumination-readings¿ method might be useful for type-tests; while another, the ¿single illumination-reading¿ method is applicable to routine tests on a particular lamp-type.