Based on today's measurements Ohms on the Y axis (vertical) against Litres along the bottom, may be of use to someone. Jon
Nice one Jon, your graph lines up perfectly with the data I've pulled from various manuals full - 34 ohms half - 90 ohms reserve - 184 ohm Test pads: 1 39 Ohms (top) 2 63 Ohms 3 90 Ohms 4 139 Ohms 5 192 Ohms 6 287 Ohms