On the Cheapstat schematic there is a jumper labeled I-V Converter. Would placing a resistance here (parallel to the 165k) increase the current limit of the TIA? Any problems with this ? eg adding 165k would give a 100micro amp limit. Or am I wrong here.

Thanks for the information. I probably need a 100micro amp range. But if a resistor change can do it, it might be worth a try.

Is it possible to use the Cheapstat in a two electrode mode to determine the I-V curve of a dye sensitized solar cell. I am new to this and if anyone has some suggestions it would be helpful.