-Introduction

Oscilloscope is an electronic measuring instrument, which can be used to observe current waveform, measure frequency and voltage waveform, etc. It is mainly composed of electron tube amplifier, scanning oscillator and cathode ray tube. Oscilloscope uses a narrow electron beam composed of high-speed electrons to hit the screen coated with fluorescent substances, which can produce tiny light spots. Under the action of the measured signal, the electron beam can draw the change curve of the measured signal on the screen.

Oscilloscopes can be divided into digital oscilloscopes and analog oscilloscopes according to different signals; According to the different structure and performance, it can be divided into ordinary oscilloscope, multifunctional oscilloscope, multi-line oscilloscope, multi-integrated oscilloscope, sampling oscilloscope, storage oscilloscope and digital oscilloscope. Although there are many kinds of oscilloscopes, their usage methods are similar. Taking SR-8 double trace oscilloscope as an example, this paper introduces the usage of the oscilloscope in detail.

Second, the use of oscilloscope-

-Panel equipment

The panel of SR-8 oscilloscope can be divided into three parts according to its position and function: display, vertical (Y axis) and horizontal (X axis). Next, the panel devices of these three parts are introduced respectively.

1, display section

The display part includes power switch, power indicator lamp, brightness (adjusting the brightness of light spot), focusing (adjusting the clarity of light spot or waveform), auxiliary focusing (adjusting the clarity with the focus knob), ruler brightness (adjusting the brightness of scale lines on the coordinate table) and tracking.

(When the key is pressed, the light spot deviating from the fluorescent screen will return to the display area, so as to find the position of the light spot) and standard signal output (square wave calibration signals of 1kHz and 1V are derived from this and added to the Y-axis input terminal to calibrate the Y-axis input sensitivity and the X-axis scanning speed).

2. Vertical (Y-axis) part

The vertical (Y-axis) part includes a display mode selection switch (for switching two Y-axis preamplifiers YA and YB

Working state), "DC- ground-AC" Y-axis input selection switch (used to select the coupling mode of the measured signal connected to the input terminal), "fine tuning V/div" sensitivity selection switch and fine tuning device, "Y-axis displacement potentiometer" (used to adjust the vertical position of the waveform), "polarity, Raya.

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Change the polarity of the channel by pulling the switch "internal trigger, pull YB"

"Trigger source selection switch and Y-axis input socket.

3. Horizontal (X-axis) part

The horizontal (X-axis) part includes "t/div" scanning speed selector switch and fine-tuning knob, "expanding×10" scanning speed expanding device and "→↓".

X-axis position adjustment knob, "external trigger, X external" socket, "trigger level" knob, "stability" trigger stability fine-tuning knob (used to change the working state of scanning circuit), "internal and external" trigger source selection switch, "AC-AC(H)-DC" trigger coupling mode switch, "high frequency-normal-automatic" trigger mode switch and "

Three. Use of oscilloscope-

-Use steps

The following details the specific steps of observing the waveform of electrical signals with an oscilloscope:

Step 1: Select Y-axis coupling mode. According to the frequency of the measured electrical signal, the "AC-ground -DC" switch selected by the Y-axis input coupling mode is set to AC or DC;

Step 2: Select Y-axis sensitivity. According to the peak value of the measured electrical signal, put the Y-axis sensitivity selection "V/div" switch at an appropriate level (in actual use, if it is not necessary to read the measured voltage value, the required height waveform can be displayed on the screen only by properly adjusting the Y-axis sensitivity fine-tuning knob);

Step 3: Select the source and polarity of the trigger signal. Usually, the trigger signal polarity switch is placed in the "+"or "-"position;

Step 4: Select the scanning speed. According to the period of the measured signal, put the X-axis scanning speed "t/div" switch at an appropriate level (in actual use, if it is not necessary to read the measured time value, just adjust the scanning speed "t/div" fine-tuning knob appropriately, and the waveform with the required number of periods can be displayed on the screen);

Step 5: Input the measured signal. The measured signal is attenuated by the probe and then input to the oscilloscope through the Y-axis input.