Toward proper evaluation of light dose in indoor office environment by frontal lux meter

Abstract

The wearable Brazilian illuminance meter "OcuLux" provides the opportunity to monitor continuously pupilar illuminance for indoor environment. The device is calibrated to evaluate the illuminance in lux for the range of 0 to 3500 lux with 23% of precision. This sensor was worn for 19 days in an office room of the LESO solar experimental building at EPFL (Lausanne, Switzerland), equipped with Anidolic Daylighting System (ADS) as well as a conventional window, to assess the light dose received by a human subject (30 year old female). The results showed that: i) the light dose is lower than the recommended values for most of the time; ii) in spite of asymmetrical workstation orientation, the light dose received during the morning and in the afternoon are comparable and iii) the impact of day length and sky condition on the light dose at the pupillary level is considerable