Luminous intensity is measured with an illuminance detector equipped with a precise front aperture and an Optometer. The luminous intensity is calculated from the measured illuminance and the solid angle resulting from the light source to aperture distance and the aperture diameter. The illuminance detector is calibrated in reference to an illuminance standard source. The optometer is calibrated in reference to a DKD calibrated current source.
A factory calibration certificate is supplied listing light source data, measurement set-up, traceability and calibration uncertainty.