we're using dual-chamber MFC in this project and connect it with multimeter (UNI-T, UT61E+ multimeter) to record the current reading (per minute) for 2 weeks. we didn't connect resistor to the circuit, so it would be hard to calculate the current if we use the multimeter to record the voltage. Plus, the current that we've obtained now only reach microampere, so I'm not sure if resistor is necessary here. Hence, we use the multimeter to only record the current, and use it to calculate the current density later. Can I do that?