How to calibrate a digital oscilloscope
1) Test steps
(a) Plug in the power cord of the oscilloscope, turn on the power switch, and the power indicator light will light up. After the scanning line appears, adjust the brightness to the appropriate position and adjust the focus control to make the scanning line the thinnest.
(b) Adjust the baseline knob so that the scan line is parallel to the horizontal scale line.
(c) Turn the fine-tuning/expansion control switch knob clockwise to the calibration position. In order to avoid measurement errors, the probe should be checked and calibrated before measurement. Calibration is: connect the probe to the correction square wave output end of the oscilloscope, and adjust the compensation capacitor of the correction hole on the probe until the square wave displayed on the screen is flat.
(d) Place the volt/degree selector switch, working mode switch, and scan time selector switch in appropriate positions according to the size, frequency, and needs of the signal being measured.
(e) Set the input coupling switch to the "GND" position and determine the position of zero level. Then put it in the "AC" position, input the measured signal from the probe, adjust the synchronization switch knob to stabilize the waveform, observe the amplitude of the signal waveform displayed in the vertical direction on the screen, the product of the measured signal voltage V/DIV and the displayed degree ;When using 10:1 input probe, the amplitude value displayed on the screen should be ×10.
2) Things to note during measurement
(a) When measuring, do not place the instrument near a place with a strong magnetic field.
(b) The amplitude of the signal being measured cannot exceed the specified withstand voltage value of each input terminal of the oscilloscope to prevent burning out the amplifier of the oscilloscope.
(c) During testing, the oscilloscope casing should be suspended to avoid short circuit.
(d) The AC voltage value measured with an oscilloscope is peak-peak value.
(e) The test line should be as short as possible and the probe should be close to the measured point, otherwise it may cause waveform distortion.
