[ADE7758] RMS gain conversion constant

Hi everyone. 

I am a newbie to ADE7758. I have got some problems:

1. I do not understand how to use Calibration for calculating conversion constant for RMS value in xVRMS and xIRMS to get the real - world value.

2. In ADE7758 datasheet, section ROOT MEAN SQUARE MEASUREMENT, am I right that I determine the value that represents the full - scale value for VRMS register at 50Hz is 0x193504 = 1 651 972d? I see other value at Table 9, but I do not understand what it really is.

3.  Also in section ROOT MEAN SQUARE MEASUREMENT, I can not see the equivalent full - scale RMS current at 50Hz.
I truly appreciate someone explain these to me.
Thanks in advance!