Lux (lumens/m2) is the SI derived unit of measure of illuminance. To accurately measure illuminance, we recommend using the PS-2177 Light Level Sensor with a PASPort interface.
None of the other light sensors offered by PASCO scientific were designed to measure illuminance.
If you wish to measure the relative light intensity as a function of wavelength, then you would need a spectrometer, such as the PS-2600 Wireless Spectrometer, instead of the PS-2177 Light Level Sensor. To obtain an absolute intensity distribution would require rigidly mounting the aperture of the spectrometer in an integrating sphere with a light source of known intensity to arrive at the proper scaling factor, and performing measurements of other light sources located at the same point as the reference.