A model of a new kind of luxmeter photometric head is designed. The luxmeter photometric head fitted with a new kind of element for spatial (angular) correction has a photometric efficiency 4.3 times higher than that of the photometric head used in current luxmeters. Thus high photometric efficiency of the photometric head enables measurements of very low illuminance. In the diffuser currently used for angular correction of the photometric head, the flux being measured is reflected and diffused several times. This type of luxmeter measuring head has a low photometric efficiency. Moreover, in this case, the light signal penetrating through the diffuser creates an electrical signal in the detector on a level comparable to its noise. This signal cannot be measured even using additional low-noise amplifiers.
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