I have a technical question, for research purposes. I have LED that we probe in AC mode. To measure the applied voltage in AC and the light-response in AC is no problem. However I would like to measure the current going through the device as well and I would like to link it to an oscilloscope. Now OSC usually measure potential (and have limited range) and I'd like to know how to have a signal directly related to the current on the OSC. If you know of any particular instrumentation please let me know.