Tips for using an oscilloscope

An oscilloscope is a very widely used electronic measuring instrument. It can transform invisible electrical signals into visible images, making it easier for people to study the changing process of various electrical phenomena.

The oscilloscope uses a narrow electron beam composed of high-speed electrons to hit the screen coated with fluorescent material to produce a tiny light spot. Under the influence of the measured signal, the electron beam is like the tip of a pen, which can describe the change curve of the instantaneous value of the measured signal on the screen. The oscilloscope can be used to observe the waveform curves of various different signal fluctuations changing over time, and it can also be used to test various different electrical quantities, such as voltage, current, frequency, phase difference, modulation fluctuation, etc.

Here are some tips for using an oscilloscope:
1. For general oscilloscopes, adjust the brightness and focus knobs to minimize the spot diameter to make the waveform clear and reduce test errors; do not let the spot stay at one point, otherwise the electron beam will hit one point and form a dark spot on the screen, damaging the screen.
2. Measurement system - such as oscilloscopes, signal sources; printers, computers and other equipment. The grounding wires of the electronic equipment under test - such as instruments, electronic components, circuit boards, and power supplies of the equipment under test must be connected to the public ground (earth).
3. When the TDS200/TDS+00/TDS2000 series digital oscilloscopes are used in conjunction with probes, only the waveform of the signal (the signal under test - the signal ground is the earth, and the output fluctuation of the signal end is less than 300VCATII) can be measured. It is absolutely impossible to measure the floating ground signal of AC220V mains or electronic equipment that cannot be isolated from AC220V mains. (The floating ground cannot be connected to the earth, otherwise it will cause damage to the instrument, such as testing an induction cooker.)
4. The outer shell of the general oscilloscope, the metal outer ring of the signal input BNC socket, the probe ground wire, and the AC220V power socket ground wire end are all connected. If the instrument is not connected to the earth wire when in use, and the probe is used directly to measure the floating signal, a potential difference will occur between the instrument and the earth; the voltage value is equal to the potential difference between the point where the probe ground wire touches the device under test and the earth. This will bring serious safety risks to the instrument operator, oscilloscope, and the electronic equipment under test.
5. If the user needs to measure switching power supplies (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 that cannot be isolated from the AC220V mains for floating signal testing, a DP+0 high-voltage isolation differential probe must be used.

Other precautions when using an oscilloscope:
(1) Thermal electronic instruments should generally avoid frequent power on and off, and the same applies to oscilloscopes.
(2) If the waveform is found to be disturbed by external interference, the oscilloscope housing can be grounded.
(3) The voltage of the "Y input" cannot be too high to avoid damage to the instrument, and it cannot exceed 400V at maximum attenuation. When the "Y input" wire is suspended, it will be disturbed by external electromagnetic interference and produce a waveform. This phenomenon should be avoided.
(4) Before shutting down, turn the brightness adjustment knob counterclockwise to the end to reduce the brightness to the minimum, and then turn off the power switch to simulate the oscilloscope.
(5) When observing the bright spots on the screen and adjusting them, the brightness of the bright spots should be moderate and not too bright.