The PC-based oscilloscope has one major thing going for it: It is much less expensive than a conventional bench-type or even hand-held oscilloscope. If the instrument were much cheaper, its developers would be paying you to take it. And PC-based devices incorporate a lot of features originally developed for the full-scale models, although many are options that are not included in the base price.
The basic unit is small – some models will fit in a shirt pocket. The scope has analog inputs so it can use probes or BNC cables connected to a signal source. After digitization and processing, the output is conveyed via USB cable to a user-supplied PC where the computer’s memory and monitor are available to display the signal(s). For this to work, the PC needs proprietary software that has been installed in advance.
Pico Technology, located in the UK, is the market leader in PC-based oscilloscopes. It manufactures dozens of models, with bandwidths ranging from a modest 5 MHz — good in the classroom — to laboratory-grade 20 GHz units. Prices run from under 100 to almost 20,000 Euros.
Active, passive and clamp-on current probes are available, as well as accelerometers, temperature and pH sensors and RF test accessories.
An extensive website includes alphabetized articles on Pico products, application notes, documentation including manuals on all models, educational experiments and videos. There is an interesting section on measurements, including information on methods for ascertaining and data logging audio signals, battery discharge, frequency, speed of light and numerous other quantities.
You might wonder why, at a modest price and with generous features, PC-based oscilloscope have not pushed aside bench and hand-held instruments. The answer lies in the fact that the PC-based oscilloscope has certain disadvantages, some inherent (obviously, for example, a PC must be dedicated to scope use when making measurements) and others subject to improvement as Pico and other manufacturers bring out new models.
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