This is the manual of the LEM-75A, I think in Spanish. I also discovered this manual on the internet, what concerns me is really the manual for the LEM-73A. The difference is that the LEM-73A has the ability to perform Ohm measurements with high and low voltage, and the LEM-75A does not. You can measure PN transitions with the high voltage (1.5 V), but not with the low voltage (88 mV). This opens up the possibility of measuring resistances without opening PN junctions. So I'm still looking for a manual for the LEM-73A.