Keithley 5 digit digital multimeter dmm voltage source meter keithley 6487 e p the keithley 6487 e is a 5 frac12 digit digital multimeter dmm voltage source meter the meter improves on the measurement capability of previous models with a 500v source voltage it provides higher accuracy and faster rise times than the 6485 as well as a damping function for use with capacitive devices p p with eight current measurement ranges and high speed autoranging this cost effective instrumen