the number the spec asks for

Kuules Meter measures loudness the way a delivery spec does — BS.1770, EBU R128 — on the way the field will be heard: a binaural render, the omni, or a 7.1.4 or 9.1.6 decode.

And where it comes from. An annulus shows the loudness by direction.
Against the target you choose. Green means on it.
One renderer in the suite, not two that drift.
Twelve directions, lit by their level.