Speed: What would be a good instrument to use to measure di/dt?

Speed: What would be a good instrument to use to measure di/dt?

It depends on the timeframe. If the time intervals are on the order of tenths of seconds or longer, picoammeters, electrometers, or SourceMeter instruments can be used. If the time intervals are very fast, use a fast current amplifier, such as the Keithley Model 428, or consider using a data acquisition board using a current shunt.