Oh OK.
I remember i tested and compared this once, because each PPP show a litle different values.
At the time , both were off a small amount, not enough for me to concern with calibration .
I believe it was off like 2 or 3 volts, but who knows if its my multimeter that is off and not the PPP ?
My PPP nº1 shows 229V, when my PPP nº2 shows 231V inputs.