Frequency Response
The NI 4070/4071/4072 uses a digital filter to ensure AC accuracy for all frequencies up to the specified limits. This filter is factory-calibrated for every AC mode and range. However, if care is not taken, it is still possible to get frequency-dependent measurement errors with the NI 4070/4071/4072. For example, a measurement of a source with a high impedance can yield lower-than-expected readings because of interaction with the input capacitance of the NI 4070/4071/4072. The NI 4070/4071/4072 accurately measures the level of the signal at its input, but the signal can be smaller than expected because of the loading effect of the capacitance. In such cases, it is advisable to either allow for the error or buffer the signal being measured.