Several multirange meters for measuring voltage and current in AC or DC are available including two large Leybold meters that can be used to monitor voltage and current in a circuit, and a large display digital multimeter that will measure voltage, current, resistance, and temperature.
Some professors have used the digital ohmmeter as a "lie-detector" -- a student volunteer was called up to answer embarrassing questions while holding the leads of the ohmmeter.
There are also large standing galvanometers, a model of a meter movement, and a measuring amplifier reading out onto a large meter for measuring small currents of 10-7 to 10-11 amps.