Owen Duffy wrote in
:

Notwithstanding the fact that the "forward power" and "reflected
power" readings are each not of stand alone, the difference between
"forward power" and "reflected power" has meaning and will be the same
for each instrument.

That reads better with the missing word supplied:

Notwithstanding the fact that the "forward power" and "reflected power"
readings are each not of stand alone meaning, the difference between
"forward power" and "reflected power" has meaning and will be the same for
each instrument.