Selecting DC Noise Rejection
Select the DC noise rejection setting by choosing one of the following:
LabVIEW—Set the DC Noise Rejection property.
CVI, C++, or Visual Basic—Set the NIDMM_ATTR_DC_NOISE_REJECTION attribute.
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Note The NI 4050 and NI 4060 are not supported. |
By default, DC Noise Rejection is set to Auto Selection (-1). When the value is Auto, the driver selects the DC Noise Rejection setting based on the resolution you configure. If you configure the NI 4070/4071/4072 with an absolute resolution that corresponds to 6½ digits (NI 4070/4072) or 7½ digits (NI 4071 only), the driver uses high-order DC noise rejection. If you configure the NI 4065 with an absolute resolution that corresponds to 6½ digits, the driver uses second-order DC noise rejection. For lower resolution DC measurements, the driver uses second-order DC noise rejection for the NI 4070/4071/4072 and normal DC noise rejection for the NI 4065. If you set the aperture time or configure the device for a waveform acquisition, the driver uses normal DC noise rejection by default. For AC measurements with the NI 4065, the driver uses second-order DC noise rejection.
Refer to DMM Measurement Defaults for more information.
| Values | Description | ||
|---|---|---|---|
| AUTO (-1) | The driver chooses the DC noise rejection setting based on the configured function and resolution. | ||
| Normal (0) | NI-DMM weighs all samples equally. | ||
| Second-Order (1) | NI-DMM weighs the samples taken in the middle of the aperture time more than samples taken at the beginning and the end of the measurement. | ||
| High-Order (2) | NI-DMM weighs the samples taken in the middle of the aperture time more than samples taken at the beginning and the end of the measurement.
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