I'm currently using the PicoLog 1000 series to test a relay circuit.
However, I have no way of measuring 0 volts. I can't ground it or short it to allow it to see 0 volts. It just jumps around between 0 and 2.5v. Any voltage above 0v works just fine. But the moment it hits 0, it jumps. And if I short it or ground it, the average voltage even RAISES.