S Class Resistors

Here we have a set of four S Class resistors manufactured by the Cambridge Instrument Company.

This design of resistor suffered from poor terminal definition, i.e. the voltage and current terminals are quite close together and hence the current distribution through the terminal block was not particularly reproducible. Close examination of the picture on the left shows that plastic washers have been fitted under some of the terminal caps. This means that the "terminals" are defined by the threaded studs and was the standard cure for this problem.