In this document, a procedure to calibrate the LED light of the Metrohm Autolab Optical Bench is presented. The procedure can be applied to the single-wavelength LED lights. Calibration is performed in order to relate the LED light intensity to the LED driver current. In this way, it is possible to correct the light intensity values when the distance between the solar cell under test and the LED light is changed. Additonally, the calibration allows the user to perform measurements on solar cells while specifying the light intensity values, instead of the LED driver current.