Oscilloscope uncertainty

Describes the sources of uncertainty to be taken into account when using an oscilloscope. In digital mode, the oscilloscope automatically digitizes the input volt- age. It quickly (up to forty million times per second) reads the input signal and stores its value in Volts in its electronic memory. When oscilloscope manufacturers specify vertical accuracy, they typically only mention bandwidth and DC accuracy.

The bandwidth specification addresses the AC accuracy.

Tighter AC accuracy specifications are very uncommon.

Measurement and uncertainty using the Multimeter.

Determination of the uncertainties of measurement. Oscilloscope calibration: examples for uncertainty of measurement . If we consider this probe as ideal (no series resistance), the voltage applied to the probe is offered directly at the input of the oscilloscope. The measurement uncertainty is now only determined by the tolerances in the attenuator, amplifier and further processing, . When calibrating oscilloscope frequency response using the swept frequency method (described above),. To do so, it is necessary to show that signal generator specifications match, or can be made to match, oscilloscope calibration requirements.

These may be factors which are not directly specified in terms of level . Abstract—We study several problems related to the characteri- zation of the timebase in high-speed sampling oscilloscopes. First, we examine the bias of using the method of the first-order approx-. If the operating conditions deviate from the reference conditions, additional measurement uncertainty contributions (see section and chapter 7) have to be included in the uncertainty budget.

During calibration, the measuring set-up must be kept in thermal equilibrium. While some oscilloscopes now use . To get our overall uncertainty we need to add the DC drift to our previous Expected Voltage calculation as shown below. Digital Multimeter Calibration. An introductory study of measurement.

Errors from nominal or variation with frequency . In addition, noise level increases and dynamic range decreases significantly with increased bandwidth. This can increase measurement uncertainty as much as inadequate bandwidth. Consequently, it is best to choose an oscilloscope with the least bandwidth for the applications.

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