HP 54750A, User Manual, Page: 441 / 478

How the Instrument W orks
System Architecture
Summary
There is no such thing as the perfect probe , so you must use some discretion
in choosing the best type of probe for each measurement.
T o make the correct choice , it's helpful to know the equivalent circuit of the
circuit under test. F or truly demanding measurements , it may be worthwhile
to simulate the eect of the probe using SPICE. This discussion assumes a
simple resistance as the equivalent circuit for the circuit under test. F or an
actual measurement, a more complete model is useful in evaluating the eects
of the probe .
Some knowledge of the expected signal, particularly its rise time or spectral
content, is also useful in making a probe choice . Finally , it's important to
know what parameter (voltage or time) you need to measure most accurately ,
because some tradeo is almost always required.
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