I set up a simple experiment to show students the DC properties of resistors, inductors and capacitors. I connected a 0.1uF capacitor in series with a 10mH inductor and a 10 Ohm resistor to drive a white LED with the DC power supply. (See figure) My goal was to show that the capacitor is an open circuit and the inductor has DC resistance. When I eliminated the capacitor, the LED lights up nicely with a DC voltage source set at 3-3.3V. I thought that students would be able to leave the circuit as is and measure the DC voltages across the inductor and resistor to estimate the value of the inductor DC resistance. Unfortunately, when I did this (with the LED still in the circuit), the relative voltage values did not reflect the resistance of the inductor. They values fluctuated some but generally predicted a much smaller inductor resistance. I could get the resistance to come out properly If I eliminated the LED and made a voltage divider out of the inductor and resistor. It appears that at least one of the wires for each measurement channel has to be connected to ground or a voltage source to get a reliable measurement. If this is the case, this limits the applicability of the M2K for determining voltages and currents in a circuit.