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The last edit to this post was made by Mackoxin Instruments - Wheat on 2020-5-8 at 15:07. At the beginning, learning any new thing always brings along many new technical terms. Getting a general understanding of the relevant technical terms before learning something new can help us achieve better results in the learning process, so that we won’t be confused when reading related articles. The same is true when learning about oscilloscopes. Next, we will introduce to you some common terms used in oscilloscopes. Explaining terms is actually very difficult; although the aim is to help newcomers who are unfamiliar with this field get up to speed quickly, term explanations often contain various other terms, which poses a challenge for learners. When explaining the terms related to oscilloscope performance in this article, every effort will be made to keep the explanation concise and clear, so that those who are just learning about oscilloscopes can gain a basic understanding and help them grasp these terms more quickly. In oscilloscope terminology related to waveforms, anything that exhibits spatial and temporal periodicity can be called a wave; a wave is a motion that is periodic in both time and space. For example, sound waves, water waves, brain waves, electromagnetic waves, etc. An oscilloscope measures the fluctuations in voltage. The period of a wave is the time taken for one repetition of that wave. A waveform is a graphical representation model of a wave. The voltage waveform shows how the voltage (Y-axis) changes over time (X-axis). We can derive a great deal of information about this signal from this waveform. From the change in waveform height, you can determine the change in voltage. If a straight line appears in a segment of the waveform, you know that the voltage did not change during that period of time. A straight diagonal line indicates that the rate of voltage increase or decrease is stable (the voltage acceleration is 0). And the sharp angles on the waveform indicate sudden changes in voltage. Below are some common voltage waveform diagrams and common waveform sources. Common voltage waveforms and their sources: Most of the waveforms that can be displayed on an oscilloscope can be classified into the following categories: sine waves, square waves and rectangular waves, sawtooth waves and triangular waves, as well as pulse waves. A sine wave is a basic waveform; the voltage waveform produced by the outlets in our homes is a sine wave, and the test signals generated by oscillators in signal generators are also usually sine waves. Most AC power sources generate sine waves. A damped oscillation waveform is a special case in which, within an oscillating circuit, the voltage gradually decreases over time. Square waves and rectangular waves: A rectangular wave is another common waveform. Simply put, a rectangular wave is a direct current voltage that turns on and off in a regular, intermittent manner. This is the standard waveform for testing amplifiers; the higher the quality of the amplifier, the lower the distortion of the square wave. Square waves are often used as timing signals in television, radio, and computer circuits. A rectangular wave is similar to a square wave; in a square wave, the positive and negative pulse widths are equal, whereas those of a rectangular wave can be arbitrary. This is particularly important in digital circuit measurements. Sawtooth and triangular waves: Sawtooth and triangular waves are generated by circuits designed for linear voltage control, such as the horizontal scanning in analog oscilloscopes or the raster scanning in televisions. The voltage of these waves changes at a constant rate. Rise and fall edges: Instantaneous changes in voltage create rise edges in the waveform, as voltage increases from low to high; for example, this occurs when you turn on a power switch. Fall edges are formed when voltage decreases from high to low, such as when you turn off a power switch. And the entire process of opening it and then closing it after a while creates a pulse. It may represent some information transmitted by the computer circuit, or it could be a fault or defect in the circuit. A whole row of consecutive pulses is called a pulse sequence; digital components in computers use pulses to communicate with each other. Pulses are also common in X-ray and communication devices. Common waveform measurement parameters of an oscilloscope: Period and frequency: If a signal is repetitive, then it has a frequency. Frequency is measured in hertz (Hz), and it represents the number of times a signal repeats itself per second. A signal that is repetitive also has a period, which refers to the time taken for one cycle within multiple repetitions of the signal. Therefore, period and frequency are reciprocals of each other. The example below is a sine wave with a frequency of 3 Hz and a period of 1/3 second. Voltage: Voltage refers to the potential or signal strength between two points in a circuit. Generally, one of these points is the ground point (0V), but this is not always the case. To measure the voltage from the maximum peak to the minimum peak of a waveform is called peak-to-peak voltage. Amplitude generally refers to the maximum voltage of the signal measured from the ground point. The waveform shown in the example below has an amplitude of 1V and a peak-to-peak voltage of 2V. Phase: Observing sine waves can provide a good explanation of the concept of phase. A circle has 360°, and the voltage of a sine wave moves in a cyclic pattern. So the period of a sine wave can also be 360°. As shown in the figure above. When you want to describe how much a waveform’s period has progressed, you can use degrees to indicate the phase angle of the sine wave. Phase shift describes the timing difference between two similar signals. As shown in the figure below, the phase of the voltage waveform with respect to the current waveform is 90°, because the distance between these two waveforms at the same point within one cycle is 1/4 of a cycle (360°/4=90°). Phase shift is very common in electronic devices.