Oscilloscope use_Oscilloscope use methods and techniques
1. Obtain the baseline: When the operator uses an oscilloscope without an instruction manual, he must first obtain the thinnest horizontal baseline before using the probe to make other measurements. The specific methods are as follows: (1) Preset the switches and knobs on the panel. Brightness is set to moderate, focus and auxiliary focus are set to moderate, vertical input coupling is set to "AC,,, vertical voltage range selection is set to 5mv/div, vertical working mode selection is set to "CHl", vertical sensitivity fine-tuning calibration position is set to "CAL, vertical channel synchronization The source selection is set to the middle position, the vertical position is set to the middle position, the A and B scan time factors are preset together at "0.5ms/div, the A scan time fine adjustment is set to the calibration position "CAL'', the horizontal position is set to the middle position, scanning working mode Set "A", the trigger synchronization mode is set to "AUTO", the slope switch is set to "+", the trigger coupling switch is set to "AC'', and the trigger source selection is set to INT. (2) Press the power switch and the power indicator light will light up. (3) Adjust the A brightness focus and other relevant control knobs to obtain a thin and bright scanning baseline. Adjust the baseline so that its position is in the middle of the screen and basically coincides with the horizontal coordinate scale. (4) Adjust the trajectory parallelism control to make the baseline parallel to the horizontal coordinates.
2. Display signal: Under normal circumstances, the oscilloscope itself has a 0.5Vp-p standard square wave signal output port. After obtaining the baseline, the probe can be connected here. At this time, there should be a series of square wave signals on the screen. Adjust the voltage. The range and sweep time factor knobs, the amplitude and width of the square wave should change. This means that the oscilloscope has been basically adjusted and can be put into use.
3． Measure the signal: Connect the test line to the CHl or CH2 input socket, touch the test probe to the test point, and then observe the waveform on the oscilloscope. If the waveform amplitude is too large or too small, adjust the voltage range knob; if the waveform period display is not suitable, adjust the scan speed knob.
Special usage methods 1. AC peak voltage measurement (1) Obtain baseline. (2) Adjust the V/div knob so that the waveform displays 5div (i.e. 5 grids) in the vertical direction. (3) Adjust "A trigger level" to obtain stable display. (4) Calculate the peak voltage using the following formula. Voltage (p-p): vertical deflection amplitude/degree x (VOLTS/div)/switch gear pole x probe attenuation magnification. For example: the measured deflection from the upper peak to the lower peak is 5.6 degrees, the VOLTS/dir switch is set to 0.5, and the x10 probe attenuation magnification is used, and the data is substituted: Voltage 2 5. 6X0.5X10228V. 2. Rise time measurement Rise time: horizontal distance (degree) x time/degree (gear)/expansion coefficient. For example: the distance between two points of the waveform is 5 degrees, the time/degree level is 1Us, x10 expansion is not expanded (i.e. x1), the given value is replaced by: rising time I division; 5X1 / 1; 51xs. 3． Phase difference measurement Phase difference: horizontal difference value (degree) x horizontal scale calibration value (degree/degree). For example: the horizontal difference is 0.6 degrees, and each degree is calibrated to 45 degrees. Substitute the given value into the formula: phase difference: 0.6x45:27
