ABSTRACT
In the first chapter we looked at how measurement inst:nnnents can produce information. The information produced and processed by these systems will be in the form of a Signal which carries a message (specific set of information). In the case of the grating spectrometer shown in figure 1.2 the signal was a voltage communicated from the light detector to the voltmeter. This voltage will vary in a specific pattern as the grating angle is altered. It is this pattern which carries the message.
