How to Compare Oscilloscopes
There are many features to consider before purchasing an oscilloscope. The price of an oscilloscope increases with accuracy of measurement. There are four major specifications to look for when comparing oscilloscopes against each other: bandwidth specifications, vertical DC gain accuracy, vertical DC gain resolution, and rise time.
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Bandwidth Specification
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The bandwidth is the maximum frequency of a measured waveform that the oscilloscope can measure. It is expresssed in Hz.
Vertical DC Gain Accuracy
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Vertical DC gain accuracy is a measure of how accurate the measurement of the displayed voltage is against the actual measured voltage. This accuracy is expressed as a percentage. If you want a more accurate measurement of a voltage level, it is suggested that you use a digital multimeter.
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DC Gain Resolution
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Modern oscilloscopes are usually digital, so they can display a waveform onscreen only as different digital logic levels. Having 4 bits would allow for 2^4, or 16, display levels, where a 5-bit system would allow for 2^5, or 32, levels. When more digital logic levels are available, the waveform appears to have a better resolution.
Rise Time Specifications
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Some waveform edges cannot be measured by an oscilloscope because they have frequency components that exceed the scope's bandwidth specification. The maximum allowed rise time specification is measured in seconds.
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References
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