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 scan line appears, adjust the brightness to the appropriate position and adjust the focus control to make the scan line as thin as possible.

(b) Adjust the baseline knob so that the scan line is parallel to the horizontal scale line.

(c) Turn the fine adjustment/expansion control switch knob clockwise to the calibration position. To avoid measurement errors, the probe should be checked and calibrated before measurement. Calibration is: connect the probe to the calibration square wave output terminal of the oscilloscope and adjust the compensation capacitor of the calibration hole on the probe until the square wave displayed on the screen is flat-topped.

(d) Place the volt/degree selector switch, operating mode switch, and scan time selector switch in appropriate positions according to the size of the signal being measured and the frequency required.

(e) Set the input coupling switch to the "GND" position to determine the position of the zero level. Then set it to the "AC" position, input the measured signal through the probe, adjust the synchronization switch knob to stabilize the waveform, and observe the amplitude of the signal waveform displayed in the vertical direction on the screen, the product of the measured signal voltage pressure V/DIV and the displayed degree; when using a 10:1 input probe, the amplitude value displayed on the screen should be ×10.

2) Matters needing attention during measurement

(a) When measuring, do not place the instrument near a strong magnetic field.

(b) The amplitude of the measured signal cannot exceed the voltage withstand value specified at each input terminal of the oscilloscope to prevent the oscilloscope amplifier from burning out.

(c) During testing, the oscilloscope housing should be suspended to avoid short circuit.

(d) The AC voltage value measured by an oscilloscope is the peak-to-peak value.

(e) The test line should be as short as possible and the probe should be close to the test point, otherwise it may cause waveform distortion.