Glossary - PICO PicoScope 2104 User Manual

PicoScope 2104 & 2105 PC Oscilloscope User Guide
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Glossary

AC/DC switch
To switch between measuring alternating current and direct current, select AC or DC
from the control on the oscilloscope toolbar of the PicoScope software application.
Choose the setting to suit the characteristics of the input signal.
Analog bandwidth
The input frequency at which the signal amplitude has fallen by 3 dB, or by half the
power, from its nominal value.
Block mode
A sampling mode in which the computer prompts the PC Oscilloscope to collect a block
of data into its internal memory before stopping the unit and transferring the whole
block into computer memory. This is the best mode to use when the input signal being
sampled contains high frequencies. Note: To avoid aliasing effects, the sampling rate
must be greater than twice the maximum frequency in the input signal.
Buffer size
The size of the PicoScope PC Oscilloscope buffer memory. The unit uses this to store
data temporarily, so that it can sample data independently of the speed at which it
can transfer data to the computer.
Driver
A software application that controls a piece of hardware. The driver for the PicoScope
2000 Series PC Oscilloscopes is supplied in the form of a 32-bit Windows DLL. This is
used by the PicoScope and PicoLog software to control the units.
ETS
Equivalent time sampling. The PicoScope 2104 and 2105 can collect data over a
number of cycles of a repetitive waveform to give a higher effective sampling rate
than is possible for a single cycle. Equivalent time sampling allows the oscilloscope to
use faster timebases than those available in real-time mode.
Maximum sampling rate
A figure indicating the maximum number of samples the unit is capable of acquiring
per second. Maximum sample rates are usually given in MS/s (megasamples per
second) or GS/s (gigasamples per second). The higher the sampling speed of the
oscilloscope, the more accurate the representation of the high-frequency details in a
fast signal.
Oversampling
A method of increasing the effective resolution of a measurement by sampling faster
than the required sampling rate, then averaging the extra samples. An oversampling
factor of four increases the effective resolution by one bit, but this increased resolution
comes at the expense of reducing the maximum sampling rate by the same factor.
PC Oscilloscope
A virtual instrument consisting of a PicoScope PC Oscilloscope and the PicoScope
software application.
PicoLog software
This is a software product that accompanies all our oscilloscopes. It turns your PC into
a data logger and chart recorder.
PicoScope 2000 Series
A range of low-cost PC Oscilloscopes that includes the PicoScope 2202 entry-level unit
and 2104 and 2105 variants.
PS2100044-1.0 Copyright 2006 Pico Technology Limited. All rights reserved.