Technical data
Table Of Contents
- Agilent 3000 Series Oscilloscopes-At a Glance
- In This Book
- Contents
- Figures
- Tables
- Getting Started
- Step 1. Inspect the package contents
- Step 2. Turn on the oscilloscope
- Step 3. Load the default oscilloscope setup
- Step 4. Input a waveform
- Step 5. Become familiar with the Front Panel Controls
- Step 6. Become familiar with the oscilloscope display
- Step 7. Use Auto-Scale
- Step 8. Compensate probes
- Step 9. Use the Run Control buttons
- Displaying Data
- Capturing Data
- Making Measurements
- Saving, Recalling, and Printing Data
- Oscilloscope Utility Settings
- Specifications and Characteristics
- Service
- Safety Notices
- Index
3Capturing Data
62 Agilent 3000 Series Oscilloscopes User’s Guide
Overview of Sampling
To understand the oscilloscope’s sampling and acquisition modes, it is
helpful to understand sampling theory, aliasing, oscilloscope bandwidth
and sample rate, oscilloscope rise time, oscilloscope bandwidth required,
and how memory depth affects sample rate.
Sampling Theory
The Nyquist sampling theorem states that for a limited bandwidth
(band- limited) signal with maximum frequency f
MAX
, the equally spaced
sampling frequency f
S
must be greater than twice the maximum frequency
f
MAX
, in order to have the signal be uniquely reconstructed without
aliasing.
f
MAX
= f
S
/2 = Nyquist frequency (f
N
) = folding frequency
Aliasing
Aliasing occurs when signals are under- sampled (f
S
< 2f
MAX
). Aliasing is
the signal distortion caused by low frequencies falsely reconstructed from
an insufficient number of sample points.