Specifications

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screen
The visual display area of an oscilloscope. It can be a CRT (a phosphor-
coated electron beam tube), an LCD (liquid crystal display), or an LED (light
emitting diode) display.
single sweep
A mode of operation of a digital scope where the scope is "armed" to wait for a
trigger event. When the trigger event occurs, the post-trigger data is collected,
the waveform is displayed, and the trigger is "disarmed".
single-shot
Used to describe the nature of capturing a transient (one time) event on an
oscilloscope.
slope
The rise over the run of a waveform. A positive sloping waveform goes up and
to the right. A negative sloping waveform goes down and to the right
(assuming the normal sweep direction is from left to right on the screen).
sweep
An older term describing the movement of the electron beam across the
screen, caused by electrostatic and magnetic fields inside of the CRT.
sweep magnifier
An analog oscilloscope feature that magnifies the trace in the horizontal (time)
direction. The magnification is usually 10 times.
sweep speed
The amount of time it takes for an electron beam to "sweep" across the screen
on an analog scope. It is given in units of time per division on the graticule.
More modern usage is to refer to the horizontal sweep circuit as the time base.
TCO
Total cost of ownership. The concept of accounting for all the costs involved in
using an instrument like an oscilloscope over the useful life of that instrument.
thermionic
emission
When certain materials are heated to a hot enough temperature, electrons can
be freed from the material and will flow in a circuit with an accelerating
potential to overcome the material's work function (the energy required to
break the electrons free of the surface). The current increases essentially as
the square of the absolute temperature of the material. This is how all
thermionic vacuum tubes like television and oscilloscope CRTs work.
time base
The circuitry used to generate the sweep of the oscilloscope (this is in the
context of an analog scope). For digital scopes, the time base controls the
sampling rate. Both circuits change the time per division setting of the scope
(i.e., how much time a unit horizontal distance on the screen represents).
trace
The display of a single waveform on an oscilloscope's screen.
transient
A signal that only occurs once or infrequently.
trigger
In an analog oscilloscope, the event or signal that causes the CRT beam to
begin its sweep across the display. In a digital oscilloscope, it's the event
around which the storage process is referenced. Some digital oscilloscopes
place the trigger in the center of the storage memory, so that there are equal
amounts of pre-trigger and post-trigger data.
In both analog and digital scopes,
versatile triggering is provided by setting the trigger type, source, level, and
slope.
trigger holdoff
An adjustable time between the end of a sweep and the moment that the
trigger circuit is armed for the next sweep. This can be valuable to get stable
displays of complex signals. The usual method is to set the holdoff to slightly
longer than the signal's period.
trigger level
The voltage level that the trigger is set to. If the trigger slope is positive, a
trigger event is generated when the trigger signal goes from less than to
greater than the trigger level. If the trigger slope is negative, a trigger event is
generated when the trigger signal goes from greater than to less than the
trigger level.
trigger mode
The mode used to trigger the scope. Two common modes are auto and
normal. Auto trigger is the same as normal triggering except when no trigger
signal is present, the scope automatically triggers itself.
trigger slope
Determines whether the scope triggers on a rising edge (positive slope) or a
falling edge (negative slope).
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