Development and implementation of photometric bench based on neutral optical density filters

We present the development of a semi-automated photometric bench implemented at the Laboratorio de Fotometria of the Centro Nacional de Metrologia of Mexico, in order to reduce the illuminance meters calibration time. This photometric bench reproduces the minimum values established in the Mexican regulation NOM-025-STPS-2008 and allows the fast calibration of the luxmeters required for illuminance levels checks. The photometric bench design uses neutral optical density filters in order to realize different illuminances at the same distance. Here we also present the uncertainty estimated for the reference illuminance values realized by the implemented photometric bench.