TABLE OF CONTENTS Ian Instone
Network analysers are complex instruments that can combine many different instruments within one measurement system. With this in mind it is easy to make apparently similar measurements with a variety of different instrument settings. Each setting may enhance one particular aspect of the measurement, but this is often traded off in another area. For example, to improve repeatability we might increase the averaging or decrease the bandwidth or use a combination of both. The resulting improvement in repeatability will usually be at the expense of the considerably increased measurement time.
This chapter discusses different types of verification which may be applied to network analyser measurements to enable the user to assess or confirm the most appropriate choice of settings on the network analyser for their particular measurement scenario.
As with calibration, it is important to understand the interpretation of the word 'verification'. The Oxford Reference Dictionary (1989) defines the word 'verify' as 'to establish the truth or correctness of by examination or demonstration; (of an event etc.) to bear out, to fulfil (a prediction or promise)'. This dictionary definition exactly describes the process of verification as applied to automatic network analysers; the quality of measurements which the analyser is capable of making is verified by comparing them with values obtained from another source, whereas calibration characterises the network analyser prior to' corrected' measurements being performed.
There are several different methods of verification so the method chosen needs...
