A Test Fixture is designed to connect packaged devices, such as transistors, diodes and ICs, to the SMUs, voltage sources, and voltage monitors on the 4145B. Eight different, interchangeable DUT Socket Boards are furnished with the Test Fixture.

The most usual, Transistor Socket Board is shown in the figure:

The SMU, Vs and Vm terminals are connected to the terminals on the DUT Socket Board with leads.