Oscilloscope use: 12 small details you must know

1. What is the most valuable indicator of an oscilloscope?
Bandwidth is a grade-level parameter. Improving bandwidth also increases cost.

2. How high should the sampling rate be to meet the requirements?
Generally speaking, the sampling rate can be 5 times the bandwidth. For example, a 200M bandwidth oscilloscope can be equipped with a 1G sampling rate.
The pursuit of a higher sampling rate is nothing more than to catch small glitches, but these high-frequency glitches have been filtered out at the bandwidth layer, and a higher sampling rate does not bring good benefits.

3. What is the difference between normal trigger and automatic trigger?
Normal: Normal (standard) trigger, waveform sampling will only be performed when there is a trigger event that meets the conditions;
Auto: Automatic trigger, after waiting for a period of time, if no trigger event that meets the conditions occurs, it will be forced to trigger and sample the waveform;

Since the trigger position is random, it often leads to unstable waveform display. If the above situation occurs, please use Normal mode.
  
4. How to capture abnormal signals whose conditions cannot be determined?
You can use template trigger to capture.

When the template trigger is turned on, the template actually acts as a layer. It will continuously detect whether there is a waveform that touches the template area. When a waveform touches the template, a signal will be detected, and then it will be filtered and displayed.

5. Are the channels of the oscilloscope isolated?
The channels of the oscilloscope are not isolated; the ground of the oscilloscope is connected to the earth and cannot be directly connected to the neutral line;
adding an isolation transformer can indeed directly measure 220V AC power, but it is not a recommended practice. The safest and most correct practice should be to use a differential probe.

6. Which is more accurate for measuring voltage, an oscilloscope or a multimeter?
The vertical resolution of a general oscilloscope is 8 bits. The measurement accuracy is related to the vertical resolution and vertical gear.
The accuracy of a multimeter is much higher. The ADC of a six-and-a-half-digit multimeter can reach 24 bits, and the ADC of a handheld meter is far more than 8 bits. The voltage value measured by a multimeter is more reliable.

7. What is the difference between the X1 and X10 positions of the oscilloscope probe?
There are two key points:
the attenuation bandwidth is different. The signal amplitude does not attenuate in the X1 position, while the signal attenuates to one tenth of the original in the X10 position. The bandwidth is different.
The bandwidth of the X1 position is only about 10M, while the bandwidth of the X10 position is about 250M.

8. Do general oscilloscope probes need to be calibrated regularly?
The standard does not have clear measurement regulations for probes, but for passive probes, at least when replacing the probe or exchanging the probe channel, the probe compensation adjustment must be performed.

9. What are the main factors that determine the price of an oscilloscope probe?
The main determinants of price are of course bandwidth and functionality.

There are many types of oscilloscope probes with different performances, such as high voltage, differential, active high-speed probes, etc., and the prices range from a few hundred RMB to nearly $10,000.

The probe is the part of the oscilloscope that contacts the circuit. A good probe can provide the fidelity required for testing. To achieve this, even a passive probe must have a lot of passive device compensation circuits (RC networks) inside.

10. Is there any way to use an oscilloscope to measure the working condition of a high-frequency transformer or inductor core?
You can rely on the power analysis software that comes with the oscilloscope. There is a function - BH curve analysis, which can reflect the working state of the core, measure the dynamic inductance value, and derive the core loss.

11. Can an oscilloscope perform Fourier decomposition?
Most modern digital oscilloscopes have FFT functions, but you need to pay attention to the number of points that FFT can analyze, which directly determines the accuracy of the FFT analysis results and avoids spectrum leakage.

12. Can the oscilloscope perform filtering? For example, low-pass filtering of PWM waves?
Oscilloscopes generally have a bandwidth limit of 20MHz, which is a hardware filter. Some oscilloscopes also support software filters with adjustable cutoff frequencies.