Abstract:
This article provides a comprehensive review of the current effective verification regulations and calibration specifications for general-purpose oscilloscopes, encompassing both analog and digital types. It systematically analyzes the metrological calibration and verification items, technical concepts, and measurement characteristics of each oscilloscope category. For analog oscilloscopes, calibration has traditionally relied on the direct reading method from screen waveforms, reflecting the combined effects of input probes, channel amplifiers, scanning circuits, high-voltage electron guns, and cathode ray tube displays. The transient nature of these waveforms makes it challenging to obtain comprehensive and effective measurements through methods other than direct screen reading. Conversely, digital oscilloscopes, built on A/D sampling technology, focus mainly on input channel amplifiers, sampling circuits, and A/D converters, with their display performance being less relevant. The measurement results, represented as saved sampling waveform sequences, allow for calibration through both direct screen reading and digital signal processing via computers. The article discusses the strengths and weaknesses of verification regulations and calibration specifications for both oscilloscope types, considering the comprehensiveness and accuracy of technical indicators, the difficulty of calibration methods and techniques, the appropriateness of automatic calibration methods, and the range of standard instruments required. The analysis provides a reference for the application, revision, improvement, and future metrological research of these regulations and specifications.