Selecting DC Noise Rejection
- Updated2023-05-10
- 2 minute(s) read
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.
By default, DC Noise Rejection is set to Auto (-1).
Considerations
- If you configure the NI 408x and NI 407x with an absolute resolution that corresponds to 6½ digits (NI 4080/4082 and NI 4070/4072) or 7½ digits (NI 4081 and NI 4071), 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 408x and NI 407x and normal DC noise rejection for the NI 4065.
- If you configure the device for a waveform acquisition, the driver uses normal
DC noise rejection by default.
For NI 407x, if you set the aperture time, 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 the DMM Measurement Defaults section for your device for more information.
| Values | Description |
|---|---|
| AUTO (-1) | NI-DMM 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. Note The NI 4065 does not support High-Order. |