A~O                P~Z

Oscilloscope Terminology (P~Z)
Peak (Vp): The maximum voltage level measured from a zero reference point.

Peak-to-peak (Vp-p): The voltage measured from the maximum point of a signal to its minimum point, usually twice the Vp level.

Period: The amount of time it takes a wave to complete one cycle. The period equals 1/frequency.

Phase: The amount of time that passes from the beginning of a cycle to the beginning of the next cycle, measured in degrees.

Phase Difference: The time expressed in degrees between the same reference point on two periodic waveforms.

Probe:  An input device, usually having a pointed metal tip for making electrical contact with a circuit element and a flexible cable for transmitting the signal to the oscilloscope.

A common waveform shape that has a fast rising edge, a width, and a fast falling edge.

Real-time Sampling: A sampling mode in which the oscilloscope collects as many samples as it can as the signal occurs.

Record Length: The record length of a digitizing oscilloscope indicates how many waveform points the oscilloscope is able to acquire for one waveform record.

Rise Time: The time taken for the leading edge of a pulse to rise from its minimum to its maximum values (typically measured from 10% to 90% of these values).

RMS: Root mean square.

Root Mean Square (RMS): Square root of the mean of the square of the signal taken during one full cycle.

Sample Point: The raw data from an ADC used to calculate waveform points.

Sample Rate: On a DSO, the sampling rate indicates how many samples per second the ADC (and therefore the oscilloscope) can acquire. Maximum sample rates are usually given in megasamples per second (MS/s).

Screen: The surface of the CRT upon which the visible pattern is produced -- the display area.

Sensitivity: A measure of the ability of a receiver to respond to weak signals.

Sensitivity Shift: A change in slope of the calibration curve due to a change in sensitivity.

Signal Generator: A device for injecting a signal into a circuit input; the circuit's output is then read by an oscilloscope.

Single Sweep: A trigger mode for displaying one screenful of a signal and then stopping.

Single Shot: A signal measured by an oscilloscope that only occurs once. It is also known as a transient event.

Slope: It is the ratio of a vertical distance to a horizontal distance on a graph or an oscilloscope screen. A positive slope increases from left to right, while a negative slope decreases from left to right.  

Spectral Filter: A filter which allows only a specific band width of the electromagnetic spectrum to pass, i.e., 4 to 8 micron infrared radiation.

Square Wave: A periodic wave that alternately assumes one of two fixed values (high and low) with the transition time between these two levels being negligible.

Sweep: One horizontal pass of an oscilloscope's electron beam from left to right across the CRT screen.

Sweep Speed: For analog oscilloscopes, this specification indicates how fast the trace can sweep across the screen, allowing you to see fine details. The fastest sweep speed of an oscilloscope is usually given in nanoseconds/div.

Switch: A device for connecting and disconnecting power to a circuit.

Trace: The visible shapes drawn on a CRT by the movement of the electron beam.

Time Base: Oscilloscope circuitry that controls the timing of the sweep. The time base is set by the seconds/division control.

Trigger: The circuit that initiates a horizontal sweep on an oscilloscope and determines the beginning point of the waveform.

Trigger Holdoff: A control that restrains the trigger circuit from looking for a trigger level for some specified time after the end of the waveform.

Trigger Level: The voltage level that a trigger source signal must reach before the trigger circuit initiates a sweep.

Voltage: Voltage is the amount of electric potential between two points in a circuit. Usually one of these points is ground  but not always.

Vertical Sensitivity: The vertical sensitivity indicates how much the vertical amplifier can amplify a weak signal. Vertical sensitivity is usually given in millivolts (mV) per division.

Waveform: A waveform is a graphic representation of a wave. A voltage waveform shows time on the horizontal axis and voltage on the vertical axis.

Waveform Capture Rate: It is rate at which an oscilloscope triggers, acquires, and displays waveforms.

Waveform Point: A digital value that represents the voltage of a signal at a specific point in time. Waveform points are calculated from sample points and stored in memory.

Z-axis: The signal in an oscilloscope that controls electron-beam brightness as the trace is formed.