Yes, that's what's described in the REW documentation:
Your SPL meter's range should be set to the value normally used for speaker level calibration and must not be altered while using REW. If you are using the Radio Shack meter, select the 80dB range if you calibrate your system at 75dB (this is the standard level recommended by DolbyTM).
Set your meter to C weighting. If you are using a microphone and preamplifier for measurement, untick the C Weighted SPL Meter box in the Mic/Meter Settings.