Oscilloscope amplitude and frequency measurements
Amplitude and Frequency Measurements (as an example of testing the calibration signal of an oscilloscope)
Insert the oscilloscope probe into the channel 1 jack and place the attenuation on the probe at ch1.
Place the channel selection in ch1 and the coupling mode in dc.
Insert the probe into the small hole of the calibration signal source, at this time, the oscilloscope screen appears light trace.
Adjust the vertical knob and horizontal knob to make the waveform displayed on the screen stable, and place the vertical trim and horizontal trim in the calibration position.
Read out the number of frames occupied by the waveform in the vertical direction and multiply it by the indicated value of the vertical attenuation knob to get the amplitude of the calibration signal.
Read out the number of frames occupied by each cycle of the waveform in the horizontal direction, multiply it by the indication value of the horizontal scanning knob to get the period of the calibration signal (the reciprocal of the period is the frequency).
General calibration signal frequency of 1khz, amplitude of 0.5v, used to calibrate the oscilloscope internal scanning oscillator frequency, if not normal, should be adjusted to the oscilloscope (internal) the corresponding potentiometer, until in line with so far.
Oscilloscope tips:
General-purpose oscilloscopes by adjusting the brightness and focus knob to make the minimum diameter of the point of light in order to make the waveform clear, reduce the test error; do not make the point of light stay at a point of immobility, otherwise the electron beam bombardment of a point is appropriate in the formation of a dark spot on the fluorescent screen, the damage to the fluorescent screen.
Measurement system - such as oscilloscopes, signal sources; printers, computers and other equipment. Measured electronic equipment - such as instruments, electronic components, circuit boards, power supply for the equipment under test, and other equipment grounding wire must be connected to the common ground (earth).
TDS200/TDS1000/TDS2000 series digital oscilloscopes used with the probe, can only measure (the signal under test - signal ground is the earth, the signal end of the output amplitude of less than 300VCATII) signal waveform. It is absolutely not possible to measure the floating ground signal of the utility AC220V or electronic equipment that cannot be isolated from the utility AC220V. (Floating ground can not be connected to the earth, or cause damage to the instrument, such as testing the induction cooker.)
General-purpose oscilloscope shell, signal input BNC socket metal ring, probe earth wire, AC220V power socket earth wire end are connected. If the instrument is not used without an earth line, directly with the probe on the floating ground signal measurement, the instrument relative to the earth will produce a potential difference; the voltage value is equal to the probe earth wire contact between the point of the equipment under test and the earth potential difference. This will bring serious safety hazards to the instrument operator, oscilloscope, the measured electronic equipment.
Must be such as the need to measure switching power supply (switching power supply primary, control circuit), UPS (uninterruptible power supply), electronic rectifiers, energy-saving lamps, inverters and other types of products or other electronic equipment and utility AC220V can not be isolated from the floating ground signal test, you must use the DP100 high-voltage isolation differential probe.
