Method for determination of the spectral mismatch correction factors for the luminous responsivity of photometers when measuring the characteristics of LED lamps

Abstract

This paper describes the challenges associated with the metrology of LED sources. The main problem is the difference between the spectra of LED lamps and the spectrums of reference lamps, which are mainly highly stable and well-reproducible incandescent lamps. The difference in spectra leads to the fact that the luminous responsivity of the calibrated photometer will be different for the reference incandescent lamp and for the LED lamp. The difference is caused by the fact that a relative spectral characteristic of the photometer responsivity is always different from the spectral responsivity of the human eye (V(λ) curve), which determines all luminous quantities. The greater the difference between the relative spectral responsivity of the photometer and V(λ) is, the more the luminous responsivity of the photometer will differ for the reference lamp and for the LED lamp. The paper describes a method developed at the NSC “Institute of Metrology” for experimental determination of mismatch correction factors of luminous responsivity that account for the difference in the LED spectra to solve the problems of metrological support of LED sources. Methods of experimental study of mismatch correction factors for measuring instruments of luminous quantities of LED radiation sources are presented.