The factory calibration of your UV-VIS-NIR Spectrometer only includes wavelength but not response (irradiance). I can measure raw data which is only usable for transmittance/reflectance measurements. How do I get irradiance measurements?

Our TE cooled Spectrometers, like the one you have, are calibrated for wavelength and not irradiance. The curve seen in the software is basically counts versus wavelength. The y-axis (counts) ranges from 0 to 2 x 16^-1M or 65535, which is dependent on integration time that the user is allowed to set via the included software. In order to calibrate the spectrometer, you need to use a calibrated light source. Out of the box, you will be able to measure transmittance/reflection measurements but, again, the units will be counts versus wavelength. If you need a spectrometer that is calibrated to provide irradiance versus wavelength readings, we offer a Compact Spectroradiometer which is designed for the 380-750nm wavelength range.