Tham khảo tài liệu 'oscilloscopes episode 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 6 Sampling oscilloscopes In addition to the ART analogue real-time oscilloscopes at which this book has looked so far there are other types of great importance in particular sampling oscilloscopes and DSOs -digital storage oscilloscopes. The latter have gained wide acceptance as the limitations of the early models have been overcome new techniques to extend their capabilities being introduced with almost bewildering speed. Chapter 7 then is devoted entirely to DSOs. But we will look first in the rest of this chapter at sampling oscilloscopes. There are four reasons for doing things in this order. First historically speaking sampling oscilloscopes predate DSOs by the best part of two decades. Second an important class of DSO - the digital sampling oscilloscope - uses exactly the same technique for capturing a repetitive very high frequency waveform as that used in the traditional sampling oscilloscope described in the remainder of this chapter. This technique is thus of extreme contemporary importance even though the type of sampling oscilloscope described below is no longer in current manufacture. Third it will enable US to clear up one phenomenon - aliasing - before tackling the increasingly complex digital storage scene. And fourth although they no longer feature in oscilloscope manufacturers catalogues there are of course many analogue sampling scopes as distinct from the later digital sampling oscilloscopes still in use. Both sampling scopes and DSOs look at an input signal at discrete sampling instants rather than continuously like an analogue real-time scope. They are therefore only aware of the state of the signal at these instants and are completely ignorant of what happens in between the samples. This ignorance is the basic cause of aliasing as will become apparent shortly. Analogue sampling oscilloscopes which I shall call simply sampling oscilloscopes from here on offer certain advantages over ordinary real-time scopes but as is always the case in .
