They're reading half the value that they should be. At least they are consistent with this. Redstone Furnace, GUI says it's pulling 20 rf/t. Multimeter measurement indicates 10. My Hydrogen Generator setup should be pumping 720 rf/t, but Multimeter shows only 360 rf/t into the Energy Cell. Electrolytic Separators pull 20 rf/t, but Multimeter indicates 10 rf/t. You get the gist. It's showing half the value. :C
