Remember the old advertising slogan? "If it works, it's a Fluke!"
In general, digital multimeters suck like a Hoover upright when trying to take readings on a DC generator/vibrating point regulator system. The meter responds too fast to changing voltages, and the digital readout "hunts" all over the place. An analog meter (with a sweep needle, not a digital readout) works much better.
Jerry
