I bought a very cheap RLC meter, mainly to measure inductance. It has a single LCD display, so it shows only one value at a time, unlike more expensive RLC meters that measure both inductance and resistance at the same time. There is only one test frequency for each measurement range, so you can't choose the test frequency.
The exact meter model is PeakTech 3730.
The meter is about as cheap as you can find. For example it lacks auto-range which is very common in decent multimeters. Instead, there is a large dial switch with separate positions for each measurement range. Apparently, the selecting the correct range from the dial isn't enough because there is also an "L/C" button which must be in the correct position for the measurement, if measuring inductance or capacitance ("L" for inductance, "C" for capacitance). At all but the 20 Henry range, it is using a fixed test frequency of 1 kHz for measurement that can't be chosen from a number of options (20 H range uses 100 Hz).
I tested how well I could separate the effects of resistance from the effects of inductance. I took an axial inductor with 56 µH nominal value and 5% accuracy. Assuming that the 56 µH nominal value is correct, it would have an inductive reactance of 0.35 ohms at that frequency.
The meter read 61 µH (actually it read 63 µH, but a measurement without any inductor with test leads shorted showed 2 µH which I subtracted).
Then I measured the resistance. It was 3.4 Ohms (actually it read 3.6 Ohms, but a measurement with test leads shorted showed 0.2 Ohms which I subtracted).
So apparently, for this inductor, total impedance is 3.4 Ohms + j*0.35 Ohms if we can believe the 56 µH nominal value to be correct. This impedance has an absolute value of 3.42 Ohms, which corresponds to an inductance of 544 µH for a cheap 1 kHz meter that's measuring only the absolute value of impedance and not the phase angle at all.
So it appears the meter is either measuring inductance by some other method than measuring impedance, or that it is measuring impedance but can somehow remove effects of resistance ten times larger than inductive reactance. The latter sounds incredible for such a cheap meter, if it's so cheap that selecting inductance from the dial isn't enough but I must press a "L/C" toggle switch too.
How does such a cheap meter measure true inductance without mixing in effects of resistance?