See here. If you’re wanting to use it with REW, measurement mics typically are small-capsule, not large like this one. It would be fine for acoustics-related measurements (you don’t even need a calibration file for those), but not necessarily for frequency response measurements.
Thanks, it is for frequency response that I was going to use it combined with the GEQ from Waves to finalize the calibration of my mixing room in the mixer position (where's it's important lol). Guess I'll have to get a calibrated mic.