A system for measuring thicknesses of a layered workpiece in a silicon integrated circuit manufacturing process. The system includes means for measuring a resistivity of said workpiece, such as an M-Gage; means for transforming a first signal set output by said means for measuring to a second signal set; and means for determining thicknesses of said workpiece layers from said resistivity capable of interpreting the second signal set. The means for transforming includes an interface board. The interface board receives the first signal set and emits the second signal set for receipt by the means for determining when an appropriate signal is received from the means for determining. [The interface board includes four inputs, first resistors connecting each of the inputs, transistors, each having a base, a collector, and an emitter, connecting each of the first resistors at the bases of the transistors, ground connecting each of the transistors at the emitters of the transistors, inverters and second resistors connecting each of the transistors at the collectors of the transistors, the second resistors each connecting a voltage source, one of the transistors connecting at the collector of the transistor a second inverter, the second inverter connecting a flip-flop, and the flip-flop connecting a second voltage source.] The interface board connects with an input/output interface card of a computer.