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Oscilloscope Terms
DIVISION
Imaginary or visible grid on the oscilloscope screen. It helps estimating signal amplitude and period.
DSO
The abbreviation for “Digital Storage Oscilloscope”.
DUAL TRACE
An oscilloscope having two traces to display channel 1 and channel 2 signals simultaneously.
6.5
- E -
EQUIVALENT TIME SAMPLING
An equivalent time sampling oscilloscope, sometimes simply called a “sampling scope,” measures
only the instantaneous amplitude of the waveform at the sampling instant. In contrast to the real-time
scope, the input signal is only sampled once per trigger.
EARTH GROUND
A conductor that connects electrical currents to the Earth.
6.6
- F -
FALLTIME
The time required for a signal to fall from 90% of the peak value to 10% of the maximum value of the
amplitude. This excludes overshoot and undershoot from measurement.
FREQUENCY (F)
The number cycles of the AC waveform per sec.
6.7
- G -
GRATICULE
The grid lines on a screen for measuring oscilloscope traces.
GROUND
A conducting connection by which an electric circuit or equipment is connected to the earth to
establish and maintain a reference voltage level. It’s also the voltage reference point in a circuit.
6.8
- H -
HERTZ (HZ)
One cycle per second. (the unit of frequency)
6.9
- I -
INPUT COUPLING
The drawing shows typical oscilloscope input circuit. There are 3 possible settings: AC-coupling, DC
coupling and GND. With AC-coupling, a capacitor is put in series with the input signal. This
capacitor blocks any DC component of the signal and passes only AC. With DC coupling, the
capacitor is bypassed and both the AC and DC component of the signal are passed. Low frequency
signals (<20Hz) should always be displayed using DC coupling. Should AC coupling be used, the
internal coupling capacitor will interfere with the signal and the displayed signal will not be correct.
